The Manual of the Botany of the Northern United States / Including the District East of the Mississippi and North of North Carolina and Tennessee

by Asa Gray

Subclass I. VASCULAR ACROGENS, or PTERIDOPHYTES.[1]

[Footnote 1: The orders of this Subclass have been elaborated anew for this edition by Prof. Daniel C. Eaton of Yale University.]

Stems containing woody fibre and vessels (especially scalariform or spiral ducts). Antheridia or archegonia, or both, formed on a minute prothallus which is developed from the spore on germination, the archegonium containing a nucleus, which after fertilization becomes an oöspore and at length grows into the conspicuous spore-bearing plant.

Order 130. EQUISETÀCEÆ. (Horsetail Family.)

Rush-like, often branching plants, with jointed and mostly hollow stems from running rootstocks, having sheaths at the joints, and, when fertile, terminated by the conical or spike-like fructification composed of shield-shaped stalked scales bearing the spore-cases beneath.—A single genus.

1. EQUISÈTUM, L. Horsetail. Scouring Rush. ([Pl. 21])

Spore-cases (sporangia, thecæ) 6 or 7, adhering to the under side of the angled shield-shaped scales of the spike, 1-celled, opening down the inner side and discharging the numerous loose spores. To the base of each spore are attached 4 thread-like and club-shaped elastic filaments, which roll up closely around the spore when moist, and uncoil when dry.—Rootstocks perennial, wide-creeping, hard and blackish, jointed, often branched and sometimes bearing small tubers. Stems erect, cylindrical, hollow, jointed; the surface striated or grooved with alternate ridges and furrows, the cuticle in most species containing silica in the form of minute granules, rosettes, or tubercles; the joints containing besides the central air-cavity a circle of smaller hollows beneath the furrows and a set of still smaller ones beneath the ridges; the nodes closed and solid, each bearing instead of leaves a sheath which is divided into teeth corresponding in number and position to the principal ridges of the stem; stomata in the furrows, each with two pairs of guard-cells, of which the outer pair is marked with radiating lines of silica. Branches, when present, in whorls from the base of the sheath, like the stem, but without the central air-cavity. Prothallus green, formed upon the ground, often variously lobed, usually diœcious. (The ancient name, from equus, horse, and seta, bristle.)

§ 1. Annual-stemmed, not surviving the winter.

[*] Fruiting in spring from soft and rather succulent pale or brownish fertile stems, the sterile stems or branches appearing later, herbaceous and very different.

[+] Fertile stems unbranched, destitute of chlorophyll and soon perishing; the sterile branching copiously.

1. E. arvénse, L. (Common H.) Fertile stems (4–10´ high) with loose and usually distant about 8–12-toothed sheaths; the sterile slender (at length 1–2° high), 10–14-furrowed, producing long and simple or sparingly branched 4-angular branches, their teeth 4, herbaceous, lanceolate.—Moist, especially gravelly soil; very common. March–May. Rootstocks often bearing little tubers.—Var. campéstre, Milde, is a not uncommon state, in which the sterile stem bears a small fruiting spike at the summit. (Eu.)

[+][+] Fertile stems when older producing herbaceous 3-sided branches, and lasting through the summer, except the naked top which perishes after fructification.

2. E. praténse, Ehrh. Sterile and finally also the fertile stems producing simple straight branches; sheaths of the stem with ovate-lanceolate short teeth, those of the branches 3-toothed; stems more slender and the branches shorter than in the last.—Mich. to Minn., and northward. April, May. (Eu.)

3. E. sylváticum, L. Sterile and fertile stems (about 12-furrowed) producing compound racemed branches; sheaths loose, with 8–14 rather blunt teeth, those of the branches bearing 4 or 5, of the branchlets 3, lance-pointed divergent teeth.—Wet shady places; common northward. May. (Eu.)

[*][*] Fruiting in summer; stems all of one kind, or the fertile contemporaneous with and like the sterile, equally herbaceous, producing mostly simple branches, or sometimes nearly naked.

4. E. palústre, L. Stems (10–18´ high) slender, very deeply 5–9-grooved, the ridges narrow and acute, roughish, the lance-awl shaped teeth whitish-margined; branches always hollow, 4–7-angled, rather few in a whorl.—Wet places, Niagara River (Clinton), Wisc. (Austin), and northward. June. (Eu.)

5. E. littoràle, Kühlewein. Stems (8–18´ high) slender, deeply 6–16-grooved, the ridges rounded, the teeth shorter than in the last, narrowly white-margined; branches often solid, 3–4-angled, 2–6 in a whorl.—Wet sandy shores, Vt. and N. Y., and northward.—Spores always abortive, whence the plant has been considered a hybrid, perhaps of E. arvense and E. limosum. July. (Eu.)

6. E. limòsum, L. ([Pl. 21], fig. 1–5.) Stems (2–5° high) slightly many-furrowed, smooth, sometimes continuing unbranched, but usually producing ascending branches after fructification; sheaths appressed, with 10–22 (commonly about 18) dark-brown and acute rigid short teeth.—In shallow water; rather common.—Air-cavities none under the grooves, but small ones under the ridges. A form in which the branches bear numerous small spikes is var. polystàchyum, Brückner. June, July. (Eu.)

§ 2. Stems all alike, evergreen, unbranched, or producing a few slender erect branches; fruiting in summer. Central air-cavity of the stem very large.

[*] Stems tall and stout (1½–4° or even 6° high), simple, or casually branched, evenly many-grooved; sheaths appressed.

7. E. hyemàle, L. (Scouring-Rush. Shave-Grass.) Stems 1½–4° high, 8–34 grooved, the ridges roughened by two more or less distinct lines of tubercles; sheaths elongated, with a black girdle above the base and a black limb; ridges of the sheaths obscurely 4-carinate, the teeth blackish, membranaceous, soon falling off.—Wet banks; common northward. Formerly in common use for polishing wood and metal. (Eu.)

8. E. robústum, Braun. Stems tall and stout (sometimes 8–10° high and nearly an inch thick), 20–48-grooved, the ridges roughened with one line of transversely oblong tubercles; sheaths rather short, with a black girdle at base and a black limb; ridges of the sheaths tricarinate, the blackish teeth soon falling off.—River-banks, Ohio and westward.

9. E. lævigàtum, Braun. Stems 1–4° high, rather slender, pale green, 14–30-grooved, the ridges almost smooth; sheath slightly enlarged upward, with a black girdle at the base of the mostly deciduous white-margined teeth, and rarely also at the base of the sheath; ridges of the sheath with one keel, or sometimes obscurely tricarinate.—By streams and in clayey places, Ohio to Minn., and westward.

[*][*] Stems slender, in tufts, 5–10-grooved; sheaths looser.

10. E. variegàtum, Schleicher. Stems ascending (6–18´ long), usually simple from a branched base, 5–10-grooved; sheaths green variegated with black above, the 5–10 teeth tipped with a deciduous bristle.—Shores or river-banks, N. H. (Bellows Falls, Carey) and Niagara to Minn., and northward; rare. (Eu.)

11. E. scirpoìdes, Michx. Stems very numerous in a tuft, filiform (3–6´ high), flexuous and curving, mostly 6-grooved, with acute ridges; sheaths 3-toothed, the bristle-pointed teeth more persistent; central air-cavity wanting.—Wooded hillsides, N. Eng. to Penn., Minn., and northward. (Eu.)

Order 131. FÍLICES. (Ferns.)

Leafy plants, with the leaves (fronds) usually raised on a stalk or petiole (stipe), rising from a (sometimes greatly elongated) rootstock, separately rolled up (circinate) in the bud, and bearing on the under surface or along the margin small reticulated sporangia, which at length split open and discharge the numerous minute spores. Prothallus green, above ground, normally monœcious.

Suborder I. Polypodiàceæ. Sporangia collected in dots, lines, or variously shaped clusters (sori or fruit-dots) on the back or margins of the frond or its divisions, cellular-reticulated, stalked, the stalk running into a vertical incomplete many-jointed ring, which by straightening at maturity ruptures the sporangium transversely on the inner side, discharging the spores. Fruit dots often covered (at least when young) by a membrane called the indusium (or less properly the involucre), growing either from the back or the margin of the frond. ([Plates 16–19.])

Tribe I. POLYPODIEÆ. Fructification on the back of the frond, in round or roundish fruit-dots (sori) placed on the veins or at the ends of the veins, without indusium of any kind. Stipes articulated to the rootstock, leaving a distinct scar when separated. Veins free (not reticulated) in our species.

1. Polypodium. Sori round, in one or more rows, on each side of the midrib or of the segments of the frond.

Tribe II. GRAMMITIDEÆ. Sori more or less elongated, without indusium, placed on the back of the frond, usually along the veins or near their extremities. Veins free in our species.

2. Notholæna. Sori short, of few rather large sporangia, placed near the tips of the veins; under surface of the frond usually either chaffy, woolly, or powdery.

Tribe III. PTERIDEÆ. Fructification marginal or intramarginal, provided with a general indusium formed of the (either altered or unchanged) margin of the frond. Stipes not articulated to the rootstock. Veins free in all our species.

[*] Sporangia at the ends of the veins, on a reflexed portion of the margin of the frond.

3. Adiantum. Midrib of the pinnules marginal or none. Stipe black and polished.

[*][*] Sporangia borne on a continuous marginal vein-like receptacle, connecting the apices of the veins, and covered by a delicate whitish indusium formed of the reflexed margin.

4. Pteris. Midrib of the pinnules central. Stipe light colored.

[*][*][*] Sporangia at or near the ends of the unconnected veins, borne on the under surface of the frond; indusium various.

5. Cheilanthes. Sori minute, at the ends of the veins; indusium continuous or interrupted. Fronds mostly chaffy, woolly, or pulverulent, rarely smooth.

6. Pellæa. Sori on the upper part of the veins, distinct, or mostly forming a confluent submarginal band of sporangia. Indusium membranaceous, continuous, rarely wanting. Sterile and fertile fronds not very unlike; stipes dark colored; fronds smooth.

7. Cryptogramme. Sori roundish or elongated and extending far down the free veins, at first covered by the very broad continuous indusium, at length exposed and confluent. Sterile and fertile fronds very different; stipes light colored; fronds smooth.

Tribe IV. BLECHNEÆ. Sori oblong or linear, borne on a veinlet parallel to the midrib, and covered with a special usually concave or arched indusium attached to the fruiting veinlet, and opening along the inner side.

8. Woodwardia. Sori forming a chain-like row each side of the midrib or central vein. Veins reticulated.

Tribe V. ASPLENIEÆ. Sori more or less elongated, occupying one or both sides of oblique veins, covered by a special indusium which is attached by one side to the fertile vein, and is free on the other. Stipes not articulated.

9. Asplenium. Sori on the upper side or rarely on both sides of a veinlet. Veins free in all our species.

10. Scolopendrium. Sori linear, confluent in pairs, each pair appearing like a single sorus with a double indusium opening down the middle. Veins free.

11. Camptosorus. Sori oblong, variously curved, or some of them in opposite pairs. Veins reticulated.

Tribe VI. ASPIDIEÆ. Sori round or roundish, on the back or rarely at the apex of the vein, with a special indusium, rarely naked. Stipes not articulated to the rootstock.

[*] Indusium obsolete or none.

12. Phegopteris. Sori round, rather small. Veins free in our species.

[*][*] Indusium evident, round or roundish, covering the sporangia, at least when young. Sterile and fertile fronds not very unlike. Veins free in our species.

13. Aspidium. Indusium flat or slightly convex, orbicular or round-reniform, fixed by the centre, opening all round the margin.

14. Cystopteris. Indusium convex, fixed by a broad base partly under the sorus, commonly reflexed as the sporangia ripen.

[*][*][*] Indusium obscure, irregularly semicircular. Fertile fronds much contracted and very unlike the sterile ones.

15. Onoclea. Sporangia on an elevated receptacle; divisions of the fertile frond pod-like or berry-like.

Tribe VII. WOODSIEÆ. Sori round, borne on the veins; indusium fixed under the sorus, divided into segments or into slender filaments.

16. Woodsia. Small ferns with free veins. Indusium very delicate.

Tribe VIII. DICKSONIEÆ. Sori roundish, marginal or submarginal. Indusium cup-shaped or two-valved, the outer portion composed of a reflexed lobule of the frond, or more or less united to it.

17. Dicksonia. Indusium in our species small, membranaceous, nearly globular. Frond elongated, decompound.

Suborder II. Hymenophyllàceæ. Sporangia sessile on a bristle-like receptacle within a cup-shaped or bivalvular involucre, the ring transverse and complete. Fronds delicately membranaceous.

18. Trichomanes. Involucres funnel-form or cup-shaped.

Suborder III. Schizæàceæ. Sporangia ovate, sessile, having a complete transverse articulated ring at the apex, and opening by a longitudinal slit. ([Pl. 19.])

19. Schizæa. Sporangia naked, fixed in a double row to the midrib of the narrow fertile segments. Sterile fronds rigid, simple or dichotomously branched.

20. Lygodium. Sporangia borne in a double row on narrow fertile segments, each sporangium seated on a separate veinlet, and provided with a special scale-like indusium. Fronds leafy, climbing.

Suborder IV. Osmundàceæ. Sporangia naked, globose, mostly pedicelled, reticulated, with no ring or mere traces of one near the apex, opening into two valves by a longitudinal slit. Stipes winged at base and almost stipulate! ([Pl. 19.])

21. Osmunda. Fertile pinnæ or fronds very much contracted, bearing the abundant and large sporangia upon the margins of the very narrow segments. Veins free.

1. POLYPÒDIUM, L. Polypody. ([Pl. 16.])

Fruit-dots round, naked, arranged on the back of the frond in one or more rows each side of the midrib or central vein, or irregularly scattered, each borne in our species on the end of a free veinlet. Rootstocks creeping, branched, often covered with chaffy scales, bearing scattered roundish knobs, to which the stipes are attached by a distinct articulation. (Name from πολύς, many, and ποῦς, foot, alluding to the branching rootstock.)

1. P. vulgàre, L. ([Pl. 16], fig. 1–3.) Fronds evergreen, oblong, smooth both sides, 4–10´ high, simple and deeply pinnatifid; the divisions linear-oblong, obtuse or somewhat acute, remotely and obscurely toothed; veins once or twice forked; fruit-dots large, midway between the midrib and the margin.—Rocks; common. July. (Eu.)

2. P. incànum, Swartz. Fronds evergreen and coriaceous, oblong, 2–6´ high, grayish and very scurfy underneath with peltate scales, simply pinnatifid; the divisions oblong-linear, obtuse; fruit-dots rather small, near the margin; veins forking, free in the N. American plant!—Rocks and trunks of trees, Va. and Ohio to Ill., and southward. Aug.

2. NOTHOLÆ̀NA, R. Brown. Cloak-fern.

Fruit-dots roundish or oblong, placed near the ends of the veins, soon more or less confluent into an irregular marginal band, with no proper involucre. Veins always free. Fronds of small size, 1–4-pinnate, the lower surface almost always either hairy, tomentose, chaffy, or covered with a fine waxy white or yellow powder. (Name from νόθος, spurious, and λαῖνα, a cloak, the woolly coating of the original species forming a spurious covering to the sporangia.)

1. N. dealbàta, Kunze. Fronds triangular-ovate, 1–3´ long, 3–4-pinnate; rhachis and branches straight, black and shining; ultimate pinnules scarcely a line long, white and powdery on the lower surface.—Clefts of calcareous rocks, Mo., Kan., and southwestward. July–Aug.

3. ADIÁNTUM, L. Maidenhair. ([Pl. 17.])

Fruit-dots marginal, short, borne on the under side of a transversely oblong, crescent-shaped or roundish, more or less altered margin or summit of a lobe or tooth of the frond reflexed to form an indusium; the sporangia attached to the approximated tips of the free forking veins.—Main rib (costa) of the pinnules none (in our species), or at the lower margin. Stipes black and polished. (The ancient name, from α privative and διαίνω, meaning unwetted, the smooth foliage repelling rain-drops.)

1. A. pedàtum, L. ([Pl. 17], fig. 1–3.) Frond forked at the summit of the upright slender stalk (9–15´ high), the recurved branches bearing on one side several slender spreading pinnate divisions; pinnules numerous, short-stalked and obliquely triangular-oblong, entire on the lower margin, from which the veins all proceed, and cleft and fruit-bearing on the other.—Rich, moist woods. July.—A delicate and most graceful Fern.

2. A. Capíllus-Véneris, L. Fronds with a continuous main rhachis, ovate-lanceolate, 9–18´ long, often pendent, 2–3-pinnate at the base, the upper third or half simply pinnate; pinnules wedge-obovate or rhomboid, 6–12´´ long, deeply and irregularly incised; veinlets flabellately forking from the base; involucres lunulate or transversely oblong.—Moist rocky places, Va. to Mo., and southward. (Eu.)

4. PTÈRIS, L. Brake or Bracken. ([Pl. 17.])

Sporangia in a continuous slender line of fructification, occupying the entire margin of the fertile frond, and covered by its reflexed narrow edge which forms a continuous membranaceous indusium, attached to an uninterrupted transverse vein-like receptacle connecting the tips of the forked free veins.—Fronds 1–3-pinnate or decompound. (The ancient Greek name of Ferns, from πτερόν, a wing, on account of the prevalent pinnate or feathery fronds.)

1. P. aquilìna, L. (Common Brake.) Frond dull green (2–3° wide), ternate at the summit of an erect stout stalk (1–2° high), the widely spreading branches twice pinnate; pinnules oblong-lanceolate; the upper undivided; the lower more or less pinnatifid, with oblong obtuse lobes, margined all round with the indusium, which is really double in this species.—Var. caudàta, with the lobes very narrow and revolute, the terminal ones much elongated, is a southern form, which extends in a modified condition as far north as New Jersey.—Thickets and hillsides, common. Aug. (Eu.)

5. CHEILÁNTHES, Swartz. Lip-fern. ([Pl. 17.])

Sporangia borne on the thickened ends of free veinlets, forming small and roundish distinct or nearly contiguous marginal fruit-dots, covered by a mostly whitish and membranaceous, sometimes herbaceous, common indusium, formed of the reflexed margin of separate lobes or of the whole pinnule.—Low, mostly with 2–3-pinnate and hairy or chaffy, rarely smooth fronds, the sterile and fertile nearly alike, the divisions with the principal vein central. Some species with continuous indusium connect this genus very closely with the next. (Name composed of χεῖλος, a lip, and ἄνθος, flower, from the shape of the indusium.)

[*] Fronds smooth, or at most hairy.

1. C. Alabaménsis, Kunze. Fronds smooth, chartaceous (2–8´ long), ovate-lanceolate, bipinnate; pinnæ numerous, oblong-lanceolate; pinnules triangular-oblong, rather acute, often auriculate or lobed; indusium continuous, rather broad, pale, and of firm consistence.—On rocks, mountains of Va. to Ky., and southward.

2. C. vestìta, Swartz. ([Pl. 17], fig. 1, 2.) Fronds (6–15´ high), lanceolate-oblong, hirsute, as are the brown and shining stipes, with straightish prominently articulated rusty hairs, twice pinnate; pinnæ rather distant, triangular-ovate; pinnules oblong, crowded (2–4´´ long), more or less incised, the ends of the roundish or oblong lobes reflexed and forming separate herbaceous involucres, which are pushed back by the ripened sporangia.—Clefts of rocks, Manhattan Island (W. W. Denslow) and N. J. to Ill., and southward.

[*][*] Fronds woolly or tomentose.

3. C. tomentòsa, Link. Fronds (12–20´ high) lanceolate-oblong, densely tomentose with slender and entangled whitish obscurely articulated hairs, thrice pinnate; primary and secondary pinnæ oblong or ovate-oblong; pinnules distinct, minute (½–1´´ long), roundish-obovate, sessile or adnate-decurrent, the upper surface less woolly, the reflexed narrow margin forming a continuous somewhat membranaceous indusium.—Mountains of Va. and Ky.; thence west and southward.—Stipe and rhachis rather stout, brown, covered with narrow chaffy scales and whitish hairs.

4. C. lanuginòsa, Nutt. Stipes slender, at first hairy, black or brown, shining; fronds (3–6´ high) ovate-lanceolate, woolly with soft whitish distinctly articulated flattened hairs, becoming smoother above, twice or thrice pinnate; pinnæ (5–6´´ long) ovate, the lowest distant, the others contiguous; pinnules crenately pinnatifid, or mostly divided into minute and roundish densely crowded segments (½–1´´ long), the herbaceous margin recurved forming an almost continuous indusium.—In dense tufts, on dry rocks and cliffs, Ill. to Minn., thence west and southward.

6. PELLÆ̀A, Link. Cliff-Brake. ([Pl. 16.])

Sporangia in roundish or elongated clusters on the upper part of the free veins, distinct, or confluent laterally so as to imitate the marginal continuous line of fructification of Pteris, commonly covered by a broad membranaceous and continuous (rarely interrupted) general indusium, which consists of the reflexed and altered margin of the fertile pinnule or division. Small ferns, with 1–3-pinnate fronds, the fertile ones with narrower divisions than the sterile, but otherwise similar. Stipes generally dark-colored, smooth and shining. (Name from πελλός, dusky, alluding to the stipe.)

1. P. grácilis, Hook. ([Pl. 16.]) Fronds smooth (3–6´ high), delicately membranaceous and slender, of few pinnæ, the lower ones once or twice pinnately parted into 3–5 decurrent divisions, those of the fertile frond oblong or linear-oblong, entire or sparingly incised; of the sterile ovate or obovate, crenate or incised; veins of the fertile fronds mostly only once forked.—Shaded calcareous rocks, Mass. to Minn., and northward; rare. July.—Rootstock very slender, creeping; stipes polished, brownish, darker and sparingly chaffy at base.

2. P. atropurpùrea, Link. Smooth, except some bristly-chaffy hairs on the midribs and especially on the dark purple and polished stalk and rhachis, 6–15´ high; frond coriaceous, pale, once or below twice pinnate; the divisions broadly linear or oblong, or the sterile sometimes oval, chiefly entire, somewhat heart-shaped or else truncate at the stalked base; veins about twice forked.—Dry calcareous rocks; not common, but of wide range. July.—Rootstock short and stout; stipes clustered.

7. CRYPTOGRÁMME, R. Brown. Rock-Brake.

Fruit-dots roundish or elongated and extending far down on the free forking veins. True involucre or indusium none, the herbaceous margins of the fertile segments at first reflexed and meeting at the midrib, at length opening out flat and exposing the confluent sporangia.—Low ferns, with smooth, 2–3-pinnate fronds, the fertile ones taller than the sterile, and with much narrower divisions. (Name from κρυπτός, hidden, and γραμμή, a line, alluding to the lines of sporangia at first concealed by the reflexed margin.)

1. C. acrostichoìdes, R. Brown. Stipes densely tufted, straw-colored; fronds 2–3-pinnate (6–10´ high); fertile segments stalked, linear or linear-oblong (3–5´´ long), the sporangia in lines extending down the veins almost to the midrib, confluent when ripe and covering the under surface of the now fully opened segments; sterile fronds on much shorter stipes, with ovate or obovate decurrent and crenately toothed or incised segments. (Allosorus acrostichoides, Sprengel.)—On rocks, from L. Superior westward and northward.—Very near C. crispa of Eu.

8. WOODWÁRDIA, Smith. Chain-fern. ([Pl. 17.])

Fruit-dots oblong or linear, arranged in one or more chain-like rows on transverse anastomosing veinlets parallel and near to the midrib. Indusium fixed by its outer margin to the fruitful veinlet, free and opening on the side next the midrib. Veins more or less reticulated, free toward the margin of the frond.—Large ferns, with pinnatifid or pinnate fronds. (Named for Thomas J. Woodward, an English botanist.)

§ 1. ANCHÍSTEA. Sterile and fertile fronds alike; veins forming only one row of meshes (areoles).

1. W. Virgínica, Smith. ([Pl. 17], fig. 4, 5.) Fronds (2–3° high) pinnate, with numerous lanceolate pinnatifid pinnæ; segments oblong; veins forming a row of narrow areoles along the midrib both of the pinnæ and of the lobes, the outer veinlets free; fruit-dots oblong, one to each areole, confluent when ripe.—Wet swamps, Maine to Ark., and southward. Rootstocks creeping, often 6–8° long! July.

§ 2. LORINSÈRIA. Sterile and fertile fronds unlike; veins of the sterile fronds forming many rows of meshes.

2. W. angustifòlia, Smith. ([Pl. 17], fig. 1–3.) Fronds pinnatifid; sterile ones (12–18´ high) with lanceolate serrulate divisions united by a broad wing; fertile fronds taller, with narrowly linear almost disconnected divisions, the areoles and fruit-dots (4–5´´ long) in a single row each side of the secondary midribs; rootstocks creeping.—Wet woods, New Eng., near the coast, to Ark., and southward; rare. Aug., Sept.

9. ASPLÈNIUM, L. Spleenwort. ([Pl. 18.])

Fruit-dots oblong or linear, oblique, separate; the straight, or rarely curved, indusium fixed lengthwise by one edge to the upper (inner) side of the fertile vein;—in some species a part of the fruit-dots are double, the fertile vein bearing two indusia placed back to back. Veins free in all our species. (Name from α- privative and σπλήν, the spleen, for supposed remedial properties.)

§ 1. ASPLENIUM proper. Indusium straight or slightly curved, attached to the upper side of the vein, rarely double.

[*] Small evergreen ferns; fronds pinnatifid, or pinnate only near the base.

1. A. pinnatífidum, Nutt. Fronds (3–6´ long) lanceolate, pinnatifid, or pinnate below, tapering above into a slender prolongation, "the apex sometimes rooting"; lobes roundish-ovate, obtuse, or the lowest pair long-acuminate; fruit-dots irregular, those next the midrib often double, even the slender prolongation fertile.—On cliffs and rocks, Penn. to Mo., and southward; very rare. July.—Resembles the Walking-Leaf (Camptosorus), but the veins are free. Stipes brownish, becoming green above, and so passing into the broad pale green midrib.

2. A. ebenoìdes, R. R. Scott. Fronds (4–9´ long) broadly lanceolate pinnatifid, below pinnate, the apex prolonged and slender; divisions lanceolate from a broad base, the lower ones shorter, often proliferous, as is the apex of the frond; fruit-dots much as in the last; stipes black and polished, as is the lower part of the midrib, especially beneath.—Limestone cliffs, Conn. and Penn., and southward; very rare, usually growing with Camptosorus and Asplenium ebeneum, of which Rev. M. G. Berkeley considered it a probable hybrid.

[*][*] Small evergreen ferns; the narrow fronds simply pinnate with numerous pinnæ.

[+] Pinnæ not auricled.

3. A. víride, Hudson. Fronds (2–5´ long) tufted, linear in outline, pale green, softly herbaceous; pinnæ roundish-ovate or ovate-rhomboid, short-stalked, crenately toothed (2–4´´ long), the midvein indistinct and forking; the slender stipe brownish and passing into a green herbaceous rhachis.—Shaded cliffs; northern New Eng., west and northward; rare. (Eu.)

4. A. Trichómanes, L. Fronds (3–8´ long) in dense spreading tufts, linear in outline, dark green and more rigid; pinnæ roundish-oblong or oval (3–4´´ long), entire or crenulate, rarely incised, unequal-sided, obliquely wedge-truncate at base, attached by a narrow point, the midvein forking and evanescent; the thread-like stipe and rhachis purple-brown and shining.—Shaded cliffs; common. July. (Eu.)

[+][+] Pinnæ more or less auricled.

5. A. párvulum, Mart. & Gal. Fronds upright (4–10´ high), narrowly linear-oblanceolate; pinnæ (2–6´´ long) rigid and thickish, mostly opposite, nearly sessile, somewhat deflexed, oblong, obtuse, entire or crenulate, auricled on the upper or both sides; sori rather few, as near the margin as the continuous midvein; stipe and rhachis black and shining.—Mountains of Va. to Mo., and southward.—Nearly intermediate between the last and the next.

6. A. ebèneum, Ait. Fronds upright (9–18´ high), linear-oblanceolate in outline, fertile ones much the taller; pinnæ (6–18´´ long) firmly membranaceous, mostly alternate, sessile, spreading, oblong or oblong-linear, finely serrate or even incised, the base auricled on the upper or both sides; sori many, nearer the elongated midvein than the margin; stipe and rhachis blackish-purple and shining.—Rocky, open woods; rather common.

[*][*][*] Small evergreen ferns; the broader fronds 1–3-pinnate; pinnæ incised.

7. A. Bradlèyi, D. C. Eaton. Fronds oblong-lanceolate, 4–7´ long, besides the blackish and somewhat shining stipe, membranaceous, pinnate; pinnæ rather numerous, the lower ones no larger than the middle ones, all short-stalked, oblong-ovate, obtuse, incised or pinnatifid into oblong toothed lobes.—On rocks, Ky. and southward; rare. A single plant has been gathered near Newburg, N. Y.—Intermediate between A. ebeneum and A. montanum.

8. A. montànum, Willd. Fronds ovate-lanceolate from a broad base (2–5´ long), subcoriaceous, pinnate; pinnæ ovate-oblong, the lowest pinnately cleft into oblong or ovate cut-toothed lobes, the upper gradually simpler; rhachis green, broad and flat; stipe brown at base.—Cliffs and rocks, from Conn. and Penn. to Ky., and southward. July.

9. A. Rùta-murària, L. Fronds deltoid-ovate (1–2½´ long), subcoriaceous, laxly 2–3-pinnate at base, the pinnæ alternate; ultimate segments few, stalked (2–5´´ long), from narrowly cuneate to roundish-obovate, toothed or incised at the apex; veins forking; sori 2–4 on a segment.—Limestone cliffs, Vt. to Mich., and southward; scarce. July. (Eu.)

[*][*][*][*] Tall ferns (2–4° high), not evergreen; fronds pinnate or sub-bipinnate.

10. A. angustifòlium, Michx. Fronds thin, simply pinnate; pinnæ numerous, short-stalked, linear-lanceolate, acuminate, entire or crenulate (3–4´ long), those of the fertile frond narrower; fruit-dots linear, 20–40 each side of the midvein; indusia slightly convex.—Rich woods, W. New Eng. to Wisc., and southward along the mountains. Sept.

11. A. thelypteroìdes, Michx. ([Pl. 18], fig. 1, 2.) Fronds (2–3° high) pinnate; pinnæ deeply pinnatifid, linear-lanceolate (3–5´ long); the lobes oblong, obtuse, minutely toothed, crowded, each bearing 3–6 pairs of oblong fruit-dots, some of them double.—Rich woods; not rare. July–Sept.

§ 2. ATHÝRIUM. Indusium delicate, curved, often crossing the vein, and attached to both sides of it, thus becoming reniform, or shaped like a horseshoe.

12. A. Filix-fœ́mina, Bernh. Fronds (1–3° high) ovate-oblong or broadly lanceolate, twice pinnate; pinnæ lanceolate, numerous; pinnules confluent on the secondary rhachis by a narrow margin, oblong and doubly serrate, or elongated and pinnately incised with cut-toothed segments; fruit-dots short, variously curved, at length confluent.—Moist woods; common and presenting many varying forms. July. (Eu.)

10. SCOLOPÉNDRIUM, Smith. Hart's-Tongue. ([Pl. 18.])

Fruit-dots linear, elongated, almost at right angles to the midrib, contiguous by twos, one on the upper side of one veinlet, and the next on the lower side of the next superior veinlet, thus appearing to have a double indusium opening along the middle. (The ancient Greek name, so called because the numerous parallel lines of fruit resemble the feet of the centipede, or Scolopendra.)

1. S. vulgàre, Smith. Frond oblong-lanceolate from an auricled-heart-shaped base, entire or wavy-margined (7–18´ long, 1–2´ wide), bright green.—Shaded ravines and under limestone cliffs; central N. Y.; also in Canada and Tenn.; very rare. Aug. (Eu.)

11. CAMPTOSÒRUS, Link. Walking-Leaf. ([Pl. 18.])

Fruit-dots oblong or linear, as in Asplenium, but irregularly scattered on either side of the reticulated veins of the simple frond, those next the midrib single, the outer ones inclined to approximate in pairs (so that their two indusia open face to face), or to become confluent at their ends, thus forming crooked lines (whence the name, from καμπτός, bent, and σωρός, for fruit-dot.)

1. C. rhizophýllus, Link. Fronds evergreen, sub-coriaceous, growing in tufts, spreading or procumbent (4–12´ long), gradually narrowed from a cordate or auricled base to a long and slender acumination, which often roots at the end and forms a new plant.—Shaded rocks, especially calcareous rocks, N. Eng. to Minn., and southward to Kan. and Ala.—The auricles are sometimes greatly elongated, and even rooting; in another form they are lacking, as in the thinner leaved C. Sibiricus. July.

12. PHEGÓPTERIS, Fée. Beech Fern.

Fruit-dots small, round, naked (no indusium), borne on the back of the veins below the apex. Stipe continuous with the rootstock.—Our species have free veins and bright green membranaceous fronds, decaying in early autumn. (Name composed of φηγός, an oak or beech, and πτερίς, fern.)

[*] Fronds twice pinnatifid; pinnæ all sessile, adnate to the winged rhachis.

1. P. polypodioìdes, Fée. Fronds triangular, longer than broad (4–9´ long), hairy on the veins, especially beneath; pinnæ linear-lanceolate, the lowest pair deflexed and standing forward; their divisions oblong, obtuse, entire, the basal decurrent upon the main rhachis; fruit-dots all near the margin.—Damp woods; common northward. July.—Rootstock slender, creeping, bearing a few distant slender stalks, rather longer than the fronds. (Eu.)

2. P. hexagonóptera, Fée. Fronds triangular, usually broader than long (7–12´ broad), slightly pubescent and often finely glandular beneath; pinnæ lanceolate; upper segments oblong, obtuse, toothed or entire, those of the very large lowest pinnæ elongated and pinnately lobed, basal ones very much decurrent and forming a continuous many-angled wing along the main rhachis; fruit-dots near the margin; some also between the sinus and the midrib.—Rather open woods, New Eng. to Minn., and southward; common. July.—Larger and broader than the last, which it often closely resembles.

[*][*] Fronds ternate, the three divisions petioled; rhachis wingless.

3. P. Dryópteris, Fée. Fronds smooth, broadly triangular (4–6´ wide); the three triangular primary divisions all widely spreading, 1–2-pinnate; segments oblong, obtuse, entire or toothed; fruit-dots near the margin.—Rocky woods; common northward. July. (Eu.)

4. P. calcàrea, Fée. Fronds minutely glandular and somewhat rigid, the lateral divisions ascending; lowest inferior pinnæ of the lateral divisions smaller in proportion than in the last species, which it otherwise closely resembles.—Iowa and Minn.; rare. July. (Eu.)

13. ASPÍDIUM, Swartz. Shield Fern. Wood Fern. ([Pl. 19.])

Fruit-dots round, borne on the back or rarely at the apex of the veins. Indusium covering the sporangia, flat or flattish, scarious, orbicular and peltate at the centre, or round-kidney-shaped and fixed either centrally or by the sinus, opening all round the margin. Stipe continuous (not articulated) with the rootstock.—Our species have free veins and 1–3-pinnate fronds. (Name, ἀσπίδιον, a small shield, from the shape of the indusium.)

§ 1. DRYÓPTERIS. Indusium reniform, or orbicular with a narrow sinus.

[*] Veins simple or simply forked and straight; fronds annual, decaying in autumn, the stalks and slender creeping rootstocks nearly naked.

1. A. Thelýpteris, Swartz. Fronds pinnate, lanceolate in outline; pinnæ horizontal or slightly recurved, linear-lanceolate, deeply pinnatifid, the lowest pairs scarcely smaller; lobes oblong, entire, obtuse or appearing acute when in fruit from the strongly revolute margins; veins mostly forked, bearing the (soon confluent) fruit-dots near their middle; indusium minute, smooth and naked.—Marshes; common. Aug.—Stalk 1° long or more, usually longer than the frond, which is of thicker texture than the next, and slightly downy. (Eu.)

2. A. Noveboracénse, Swartz. Fronds pinnate, lanceolate in outline, tapering both ways from the middle; pinnæ lanceolate, the lowest 2 or more pairs gradually shorter and deflexed; lobes flat, oblong, basal ones often enlarged and incised; veins simple, or forked in the basal lobes; fruit-dots distinct, near the margin; indusium minute, the margin glanduliferous.—Swamps and moist thickets; common. July.—Frond pale green, delicate and membranaceous, hairy beneath along the midribs and veins.

[*][*] Veins, at least the lowest, more than once forked or somewhat pinnately branching; fruit-bearing veinlets often obscure or vanishing above the fruit-dot; fronds, at least the sterile ones, often evergreen; stalks and apex of the thickened rootstock scaly or chaffy, and often the main rhachis also.

[+] Fronds small, pinnate; pinnæ pinnatifid; indusia very large, persistent.

3. A. fràgrans, Swartz. Fronds (4–12´ high) glandular and aromatic, narrowly lanceolate, with linear-oblong pinnately-parted pinnæ; their crowded divisions (2´´ long) oblong, obtuse, toothed or nearly entire, nearly covered beneath with the very large thin imbricated indusia, which are orbicular with a narrow sinus, the margin sparingly glanduliferous and often ragged.—On rocks, especially near waterfalls, mountains of northern New Eng., west and northward.—Rootstock stout, nearly erect, densely chaffy, as are the crowded stipes and rhachis. (Asia, and barely reaching S. E. Eu.)

[+][+] Large (1–2½° high), the fronds mostly twice pinnate with variously toothed and incised pinnules; indusia rather small, shrivelled in age, or deciduous.

4. A. spinulòsum, Swartz. Stipes with a few pale-brown deciduous scales; frond ovate-lanceolate, twice pinnate; pinnæ oblique to the rhachis, elongated-triangular, the lower pairs broadly triangular; pinnules set obliquely on the midribs, connected by a very narrow wing, oblong, acute, incisely serrate or pinnatifid with spinulosely-toothed lobes; indusium smooth and without marginal glands.—In damp woods, New Eng. to Ky., and northward. July.—The common European type, rare in North America. (Eu.)

Var. intermèdium, D. C. Eaton. Scales of the stipe few, brown with a darker centre; frond broadly oblong-ovate, twice or often thrice pinnate; pinnæ spreading, oblong-lanceolate, the lower unequally triangular-ovate; pinnules crowded, ovate-oblong, spreading, pinnately divided; the oblong lobes spinulose-toothed at the apex; margin of the indusium denticulate and beset with minute stalked glands.—Woods, everywhere.

Var. dilatàtum, Hook. Scales of the stipe large, brown with a dark centre; frond broader, ovate or triangular-ovate in outline, oftenest thrice pinnate; pinnules lance-oblong, the lowest often much elongated; indusium (in the North American plant) smooth and naked.—A dwarf state, fruiting when only 5–8´ high, answers to var. dumetorum.—N. New Eng. to Minn., chiefly in mountain woods, and northward. (Eu.)

5. A. Boòttii, Tuckerman. Scales of the stipe pale-brown; fronds (1–2½° long) elongated-lanceolate in outline, somewhat narrowed at base; lowest pinnæ triangular-ovate, the upper longer and narrower; pinnules oblong-ovate, sharply spinulose-serrate or the lower pinnatifid; indusium minutely glandular. (A. spinulosum, var. Boottii, of last ed. A. cristatum, var. uliginosum, Milde.)—Wet thickets and about ponds, New Eng. to Del. and Minn. July.—Sterile fronds much smaller and simpler than the fertile. (Eu.)

[+][+][+] Large (2–4° high); fronds once pinnate and the pinnæ deeply pinnatifid, or nearly twice pinnate; fruit-dots not very near the margin; the indusium large, thinnish and flat, persistent.

6. A. cristàtum, Swartz. Frond linear-oblong or lanceolate in outline (1–2° long); pinnæ short (2–3´ long), triangular-oblong, or the lowest nearly triangular-ovate, from a somewhat heart-shaped base, acute, deeply pinnatifid; the divisions (6–10 pairs) oblong, very obtuse, finely serrate or cut-toothed, the lowest pinnatifid-lobed; fruit-dots as near the midvein as the margin; indusium round-reniform, the sinus mostly shallow, smooth and naked.—Swamps, etc.; common. July.—Stipes and the stout creeping rootstock bearing broad and deciduous chaffy scales. (Eu.)

Var. Clintoniànum. Frond in every way much larger (2½–4° long); pinnæ oblong-lanceolate, broadest at base (4–6´ long, 1–2´ broad), deeply pinnatifid; the divisions (8–16 pairs) crowded or distant, linear-oblong, obtuse, obscurely serrate or cut-toothed, the basal sometimes pinnately lobed; veins pinnately forking, the lowest anterior veinlets bearing the fruit-dots near the midvein; indusium orbicular with a shallow sinus, smooth and naked.—Swampy woods, New Eng. to N. J., N. Y. (G. W. Clinton, etc.), and westward. July.—Rootstock stout, creeping, chaffy (like the stipes) with large bright-brown scales. A showy fern, unlike any European form of A. cristatum, and often mistaken for A. Goldianum.

7. A. Goldiànum, Hook. Frond broadly ovate, or the fertile ovate-oblong in outline (2–3° long); pinnæ (6–9´ long), oblong-lanceolate, broadest in the middle, pinnately parted; the divisions (about 20 pairs) oblong-linear, slightly scythe-shaped (9–15´´ long), serrate with appressed teeth; veins pinnately forking and bearing the fruit-dots very near the midvein; indusium very large, orbicular with a deep narrow sinus, smooth and without marginal glands.—Rich and moist woods, from Conn. to Ky., and northward. July.—A stately fern, often 4° high, the fronds growing in a circle from a stout ascending chaffy rootstock, and decaying in autumn. Indusium with the sides of the sinus often overlapping, thus appearing to be round and entire as in § Polystichum.

[+][+][+][+] Large (1–3° high); stipes very chaffy at base; fronds twice pinnate, but the upper pinnules confluent, some of the lower pinnatifid-toothed; fruit-dots rather large; indusium convex, without marginal glands, persistent.

8. A. Fílix-mas, Swartz. Frond lanceolate in outline (1–3° high); pinnæ linear-lanceolate, tapering from base to apex; pinnules oblong, very obtuse, serrate at the apex and obscurely so at the sides, the basal incisely lobed, distinct, the upper confluent; fruit-dots nearer the midvein than the margin, and usually confined to the lower half of each fertile pinnule.—Rocky woods, N. Mich. to Dak. and Col.—Frond thickish but not surviving the winter. (Eu.)

9. A. marginàle, Swartz. ([Pl. 19], fig. 1, 2.) Frond evergreen, smooth, thickish and almost coriaceous, ovate-oblong in outline (1–2° long); pinnæ lanceolate, acuminate, slightly broadest above the base; pinnules oblong or oblong-scythe-shaped, crowded, obtuse or pointed, entire or crenately-toothed; fruit-dots close to the margin.—Rocky hillsides in rich woods; common, especially northward. Aug.

§ 2. POLÝSTICHUM. Indusium orbicular and entire, peltate, fixed by the depressed centre; fronds rigid and coriaceous, evergreen, very chaffy on the rhachis, etc.; pinnæ or pinnules auricled at base on the upper side, crowded, the teeth or lobes bristle-tipped.

[*] Fronds simply pinnate.

10. A. acrostichoìdes, Swartz. (Christmas Fern.) ([Pl. 19], fig. 3, 4.) Frond lanceolate (1–2½° high), stalked; pinnæ linear-lanceolate, somewhat scythe-shaped, half-halberd-shaped at the slightly stalked base, serrulate with appressed bristly teeth; the fertile (upper) contracted and smaller, bearing contiguous fruit-dots near the midrib, which are confluent with age, covering the surface.—Var. incìsum is a state with cut-lobed pinnæ, a not unfrequent case in the sterile fronds; sometimes with all the tips fertile.—Common in rocky woods, especially northward. July.

11. A. Lonchìtis, Swartz. Frond linear-lanceolate (9–20´ high), scarcely stalked, very rigid; pinnæ broadly lanceolate-scythe-shaped, or the lowest triangular, strongly auricled on the upper side, and wedge-truncate on the lower, densely spinulose-toothed (1´ or less in length), copiously fruit-bearing; fruit-dots contiguous and near the margins.—Woods, southern shore of Lake Superior, and northward. (Eu.)

[*][*] Fronds bipinnate.

12. A. aculeàtum, Swartz, var. Braùnii, Koch. Fronds spreading (1½–2° long), oblong-lanceolate in outline, with a tapering base, the lower of the many pairs of oblong-lanceolate pinnæ gradually reduced in size and obtuse; pinnules ovate or oblong, obtuse, truncate and almost rectangular at base, short-stalked, or the upper confluent, sharply toothed, beset with long and soft as well as chaffy hairs.—Deep woods, mountains of New Eng., N. Y., and Penn., and northward. (Eu.)

14. CYSTÓPTERIS, Bernhardi. Bladder Fern. ([Pl. 19.])

Fruit-dots roundish, borne on the back of a straight fork of the free veins; the delicate indusium hood-like or arched, attached by a broad base on the inner side (toward the midrib) partly under the fruit-dot, early opening free at the other side, which looks toward the apex of the lobe, and is somewhat jagged, soon thrown back or withering away.—Tufted ferns with slender and delicate 2–3-pinnate fronds; the lobes cut-toothed. (Name composed of κύστις, a bladder, and πτερίς, fern, from the inflated indusium.)

1. C. bulbífera, Bernh. ([Pl. 19], fig. 1–3.) Frond lanceolate, elongated (1–2° long), 2-pinnate; the pinnæ lanceolate-oblong, pointed, horizontal (1–2´ long); the rhachis and pinnæ often bearing bulblets underneath, wingless; pinnules crowded, oblong, obtuse, toothed or pinnatifid; indusium short, truncate on the free side.—Shaded ravines, not rare from N. Eng. to Ark., commoner on calcareous rocks. July.—Specimens from Tenn. and Ark. have sometimes shorter fronds and few or no bulblets, indicating an approach to the next species.

2. C. frágilis, Bernh. Frond oblong-lanceolate (4–8´ long, besides the brittle stalk which is fully as long), 2–3-pinnate; the pinnæ and pinnules ovate or lanceolate in outline, irregularly pinnatifid or cut-toothed, mostly acute, decurrent on the margined or winged rhachis; indusium tapering or acute at the free end.—Shaded cliffs and rocky woods; common and greatly varying in the shape and cutting of the pinnules. July. (Eu.)

15. ONOCLÈA, L. ([Pl. 16] and 19.)

Sporangia borne on elevated receptacles, forming roundish sori imperfectly covered by very delicate hood-shaped indusia attached to the base of the receptacles. Fertile fronds erect, rigid, with contracted pod-like or berry-like divisions at first completely concealing the sporangia, and at last, when dry and indurated, cracking open and allowing the spores to escape. Sterile fronds foliaceous. Rootstocks creeping and constantly forming new plants. (Name apparently from ὄνος, a vessel, and κλείω, to close, from the singularly rolled up fructification.)

§ 1. ONOCLEA proper. Sterile frond with anastomosing veins.

1. O. sensíbilis, L. (Sensitive Fern.) ([Pl. 19], fig. 1, 2.) Fronds scattered; the sterile ones long-stalked (2–15´ long), triangular-ovate, pinnatifid into a few oblong-lanceolate sinuately lobed or nearly entire segments; veins reticulated with fine meshes; fertile fronds contracted, closely bipinnate, the pinnules rolled up into berry-like bodies.—Moist meadows and thickets, very common and variable. July.—Imperfectly fertile fronds sometimes occur, with the still foliaceous pinnæ cut into obovate segments with free veins and abortive sori; the so-called var. obtusilobàta.

§ 2. STRUTHIÓPTERIS. Sterile frond with free veins.

2. O. Struthiópteris, Hoffmann. ([Pl. 16], fig. 1–5.) Fronds growing in a crown; sterile ones short-stalked (2–10° high), broadly lanceolate, narrowed toward the base, pinnate with many linear-lanceolate, pinnatifid pinnæ; veins free, the veinlets simple; fertile frond shorter, pinnate with pod-like or somewhat necklace-shaped pinnæ. (Struthiopteris Germanica, Willd.)—Alluvial soil, common northward. July.—The rootstock sends out slender underground stolons, which bear fronds the next year. (Eu.)

16. WOÓDSIA, R. Brown. ([Pl. 19.])

Fruit-dots round, borne on the back of simply-forked free veins; the very thin and often evanescent indusium attached by its base all around the receptacle, under the sporangia, either small and open, or else early bursting at the top into irregular pieces or lobes.—Small and tufted pinnately-divided ferns. (Dedicated to Joseph Woods, an English botanist.)

[*] Stalks obscurely articulated some distance from the base; fronds chaffy or smooth, never glandular; indusium divided nearly to the centre into slender hairs which are curled over the sporangia.

1. W. Ilvénsis, R. Brown. Frond oblong-lanceolate (2–6´ long by 12–18´´ wide), smoothish and green above, thickly clothed underneath as well as the stalk with rusty bristle-like chaff, pinnate; the pinnæ crowded, oblong, obtuse, sessile, pinnately parted, the numerous crowded segments oblong, obtuse, obscurely crenate; the fruit-dots near the margin, somewhat confluent when old.—Exposed rocks; common, especially northward, and southward in the Alleghanies. June. (Eu.)

2. W. hyperbòrea, R. Brown. Frond narrowly oblong-lanceolate (2–6´ long by 8–12´´ wide), smooth above, sparingly paleaceous-hirsute beneath, pinnate; the pinnæ triangular-ovate, obtuse, pinnately lobed, the lobes few and nearly entire; fruit-dots rarely confluent.—Mountain ravines, northern Vt. and N. Y., and northward; rare. (Eu.)

3. W. glabélla, R. Brown. ([Pl. 19], fig. 1–3.) Smooth and naked throughout; frond linear and very delicate (2–5´ high), pinnate; pinnæ roundish-ovate, the lower ones rather remote (2–4´´ long), obtuse, crenately lobed; fruit-dots scanty; the hairs of the indusium fewer than in the last two species.—On moist mossy rocks, mountains of northern New Eng., north and westward. First found at Little Falls, N. Y., by Dr. Vasey. (Eu.)

[*][*] Stalks not articulated; fronds never chaffy, often glandular-pubescent.

[+] Indusium of a few broad segments, at first covering the sorus completely.

4. W. obtùsa, Torr. ([Pl. 19], fig. 4, 5.) Frond broadly lanceolate, minutely glandular-hairy (6–12´ high), pinnate, or nearly twice pinnate; pinnæ rather remote, triangular-ovate or oblong (1–2´ long), bluntish, pinnately parted; segments oblong, obtuse, crenately toothed, the lower pinnatifid with toothed lobes; veins forked, and bearing the fruit-dots on or below the minutely toothed lobes; indusium at length splitting into several spreading jagged lobes.—Rocky banks and cliffs; not rare.

[+][+] Indusium entirely concealed beneath the sorus, divided into very narrow segments or reduced to minute hairs.

5. W. Oregàna, D. C. Eaton. Smooth, with fronds (2–8´ high, 8–12´´ wide) elliptical-lanceolate, pinnate, the fertile ones tallest; pinnæ triangular-oblong, obtuse, pinnatifid; segments oblong or ovate, obtuse, finely toothed, and in larger fronds incised; fruit-dots near the margin; indusium very small, divided almost to the centre into a few necklace-like-jointed cilia.—Crevices of rocks, south shore of Lake Superior (Robbins), and westward.

6. W. scopulìna, D. C. Eaton. Much like the last, but the rather larger fronds puberulent beneath with minute jointed hairs and stalked glands; indusium deeply cleft into narrow segments ending in jointed hairs.—Rocky places, Minn., southward and westward.

17. DICKSÒNIA, L'Her. ([Pl. 17.])

Fruit-dots small, globular, marginal, each placed on the apex of a free vein or fork; the sporangia borne on an elevated globular receptacle, enclosed in a membranaceous cup-shaped indusium which is open at the top, and on the outer side partly adherent to a reflexed toothlet of the frond. (Named for James Dickson, an English Cryptogamic botanist.)

1. D. pilosiúscula, Willd. Fronds minutely glandular and hairy (2–3° high), ovate-lanceolate and acuminate in outline, pale green, very thin, with strong chaffless stalks rising from slender extensively creeping naked root-stocks, mostly bipinnate; primary pinnæ lanceolate, pointed, the secondary pinnatifid into oblong and obtuse cut-toothed lobes; fruit-dots minute, each on a recurved toothlet, usually one at the upper margin of each lobe. (D. punctilobula, Kunze.)—Common in moist and shady places, from New Eng. to Minn.—Frond sweet-scented in drying.

18. TRICHÓMANES, L. Filmy Fern.

Sporangia with a transverse entire ring, sessile on a cylindrical receptacle which is produced from the end of a vein and enclosed in a funnel-form or cup-shaped involucre of the same substance with the frond. Fronds very thin and pellucid, often consisting of a single layer of cells. (An ancient Greek name for some fern.)

1. T. radìcans, Swartz. Fronds very delicate, oblong-lanceolate in outline (4–8´ long, 6–18´´ wide), bipinnatifid; rhachis narrowly winged; pinnæ triangular-ovate, the divisions toothed or again lobed; involucres tubular-funnel-shaped, margined, the mouth truncate; receptacle often much exserted.—On moist and dripping sandstone cliffs, Ky., and southward; rare.—Though the fronds are so very delicate, yet they survive for several years; they begin to fruit the second or third year, and thereafter the receptacle continues to grow and to produce new sporangia at its base. (Eu.)

19. SCHIZÆ̀A, Smith. ([Pl. 20.])

Sporangia large, ovoid, striate-rayed at the apex, opening by a longitudinal cleft, naked, vertically sessile in a double row along the single vein of the narrow divisions of the pinnate (or radiate) fertile appendages to the slender and simply linear, or (in foreign species) fan-shaped or dichotomously many-cleft fronds (whence the name, from σχίζω, to split).

1. S. pusílla, Pursh. Sterile fronds linear, very slender, flattened and tortuous; the fertile ones equally slender (¼´´ wide), but taller (3–4´ high), and bearing at the top the fertile appendage, consisting of about 5 pairs of crowded pinnæ (each 1–1½´´ long).—Low grounds, pine barrens of N. J.; very local. Sept. (Also in Nova Scotia and Newf.)

20. LYGÒDIUM, Swartz. Climbing Fern. ([Pl. 20.])

Fronds twining or climbing, bearing stalked and variously lobed (or compound) divisions in pairs, with mostly free veins; the fructification on separate contracted divisions or spike-like lobes, one side of which is covered with a double row of imbricated hooded scale-like indusia, fixed by a broad base to short oblique veinlets. Sporangia much as in Schizæa, but oblique, fixed to the veinlet by the inner side next the base, one or rarely two covered by each indusium. (Name from λυγώδης, flexible.)

1. L. palmàtum, Swartz. Very smooth; stalks slender, flexile and twining (1–3° long), from slender running rootstocks; the short alternate branches or petioles 2-forked; each fork bearing a round-heart-shaped palmately 4–7-lobed frondlet; fertile frondlets above, contracted and several times forked, forming a terminal panicle.—Low moist thickets and open woods, Mass. to Va., Ky., and sparingly southward; rare. Sept.

21. OSMÚNDA, L. Flowering Fern. ([Pl. 20.])

Fertile fronds or fertile portions of the frond destitute of chlorophyll, very much contracted, and bearing on the margins of the narrow rhachis-like divisions short-pedicelled and naked sporangia; these are globular, thin and reticulated, large, opening by a longitudinal cleft into two valves, and bearing near the apex a small patch of thickened oblong cells, the rudiment of a transverse ring.—Fronds tall and upright, growing in large crowns from thickened rootstocks, once or twice pinnate; veins forking and free. Spores green. (Osmunder, a Saxon name of the Celtic divinity, Thor.)

[*] Sterile fronds truly bipinnate.

1. O. regàlis, L. (Flowering Fern.) Very smooth, pale green (2–5° high); sterile pinnules 13–25, varying from oblong-oval to lance-oblong, finely serrulate, especially toward the apex, otherwise entire, or crenately lobed toward the rounded, oblique and truncate, or even cordate and semi-auriculate base, sessile or short-stalked (1–2´ long); the fertile racemose-panicled at the summit of the frond.—Swamps and wet woods; common. The cordate pinnules sometimes found here are commoner in Europe. May, June. (Eu.)

[*][*] Sterile fronds once pinnate; pinnæ deeply pinnatifid; the lobes entire.

2. O. Claytoniàna, L. ([Pl. 20], fig. 1–3.) Clothed with loose wool when young, soon smooth; fertile fronds taller than the sterile (2–4° high); pinnæ oblong-lanceolate, with oblong obtuse divisions; some (2–5 pairs) of the middle pinnæ fertile, these entirely pinnate; sporangia greenish, turning brown.—Low grounds, common. May.—Fruiting as it unfolds.

3. O. cinnamòmea, L. (Cinnamon Fern.) Clothed with rusty wool when young; sterile fronds tallest (at length 3–5° high), smooth when full grown, the lanceolate pinnæ pinnatifid into broadly oblong obtuse divisions; fertile fronds separate, appearing earlier from the same rootstock and soon withering (1–2° high), contracted, twice pinnate, covered with the cinnamon-colored sporangia.—Var. frondòsa is a rare occasional state, in which some of the fronds are sterile below and more sparsely fertile at their summit, or rarely in the middle.—Swamps and low copses, everywhere. May.

Order 132. OPHIOGLOSSÀCEÆ. (Adder's-Tongue Family.)

Leafy and often somewhat fleshy plants; the leaves (fronds) simple or branched, often fern-like in appearance, erect in vernation, developed from underground buds formed either inside the base of the old stalk or by the side of it, and bearing in special spikes or panicles rather large subcoriaceous bivalvular sporangia formed from the main tissue of the fruiting branches. Prothallus underground, not green, monœcious.—A small order, separated from Ferns on account of the different nature of the sporangia, the erect vernation, etc.

1. Botrychium. Sporangia in pinnate or compound spikes, distinct. Veins free.

2. Ophioglossum. Sporangia cohering in a simple spike. Veins reticulated.

1. BOTRÝCHIUM, Swartz. Moonwort. ([Pl. 20.])

Rootstock very short, erect, with clustered fleshy roots (which are full of starch, in very minute, irregular granules!); the base of the naked stalk containing the bud for the next year's frond; frond with an anterior fertile and a posterior sterile segment; the former mostly 1–3-pinnate, the contracted divisions bearing a double row of sessile naked sporangia; these are distinct, rather coriaceous, not reticulated, globular, without a ring, and open transversely into two valves. Sterile segment of the frond ternately or pinnately divided or compound; veins all free. Spores copious, sulphur-color. (Name a diminutive of βότρυς, a cluster of grapes, from the appearance of the fructification.)

§ 1. BOTRYCHIUM proper. Base of the stalk containing the bud completely closed; sterile segment more or less fleshy; the cells of the epidermis straight.

[*] Sterile portion of the frond sessile or nearly so at or above the middle of the plant. Plants small.

1. B. Lunària, Swartz. Sterile segment nearly sessile, borne near the middle of the plant, oblong, simply pinnate with 5–15 lunate or fan-shaped very obtuse crenate, incised or nearly entire, fleshy divisions, more or less excised at the base on the lower or on both sides, the veins radiating from the base and repeatedly forking; fertile segment panicled, 2–3-pinnate.—N. Eng. to Lake Superior, and northward; rare.—Very fleshy, 4–10´ high. (Eu.)

2. B. símplex, Hitchcock. Fronds small (2–4´, rarely 5–6´ high), the sterile segment short-petioled from near the middle of the plant, thickish and fleshy, simple and roundish, or pinnately 3–7-lobed; the lobes roundish-obovate, nearly entire, decurrent on the broad and flat indeterminate rhachis; the veins all forking from the base; fertile segment simple or 1–2-pinnate.—Maine to N. Y., Minn., and northward; rare. (Eu.)

3. B. lanceolàtum, Angstroem. Fronds small (3–10´ high); the sterile segment closely sessile at the top of the long and slender common stalk, scarcely fleshy, triangular, ternately twice pinnatifid; the acute lobes lanceolate, incised or toothed; veinlets forking from a continuous midvein; fertile part 2–3-pinnate. —N. Eng. and N. J. to Ohio and Lake Superior. July–Aug. (Eu.)

4. B. matricariæfòlium, Braun. Fronds small (3–10´ high); the sterile segment nearly sessile at the top of the long and slender common stalk, moderately fleshy, ovate or triangular, varying from pinnate to bipinnatifid; the lobes oblong-ovate and obtuse; midvein dissipated into forking veinlets; fertile part 2–3-pinnate.—Same range as the last. June, July. (Eu.)

[*][*] Sterile portion of the frond long-stalked; the common stalk short in proportion to the size of the plant. Plants usually larger.

5. B. ternàtum, Swartz. ([Pl. 20.]) Plant very fleshy (4–16´ high), sparsely hairy; sterile segment long-petioled from near the base of the plant, broadly triangular, ternate and variously decompound with stalked divisions; ultimate segments varying from roundish-reniform and sub-entire to ovate-lanceolate and doubly incised; fertile segment erect, 2–4-pinnate.—The following varieties pass into each other:—Var. austràle; frond ample; ultimate segments rhomboid-ovate with a denticulate margin.—Var. intermèdium; frond of moderate size; ultimate segments as in var. australe. (B. lunarioides, of last ed.)—Var. rutæfòlium; frond small; ultimate segments few, ovate and semicordate.—Var. lunarioìdes; frond small; ultimate segments roundish-reniform.—Var. oblìquum; frond moderate; ultimate segments obliquely lanceolate, denticulate or toothed.—Var. disséctum; segments dissected into innumerable narrow lobes or teeth.—Pastures and hillsides, sometimes in dry woods, rather common, especially vars. intermedium and obliquum.—Var. rutæfolium occurs in Europe.

§ 2. OSMUNDÓPTERIS. Base of the stalk containing the bud open along one side; sterile segment membranaceous; the cells of the epidermis flexuous.

6. B. Virginiànum, Swartz. Fronds tall and ample; sterile segment sessile above the middle of the plant, broadly triangular, thin and membranaceous, ternate; the short-stalked primary divisions once or twice pinnate, and then once or twice pinnatifid; the oblong lobes cut-toothed toward the apex; veins forking from a midvein; fertile part 2–3-pinnate.—Rich woods; common. —Plant 1–2° high, or often reduced to a few inches, in which case it is B. gracile, Pursh. June, July. (Eu.)

2. OPHIOGLÓSSUM, L. Adder's-Tongue. ([Pl. 20.])

Rootstock erect, fleshy and sometimes tuberous, with slender fleshy roots which are sometimes proliferous; bud placed by the side of the base of the stalk; fronds with anterior and posterior segments as in Botrychium, but the coriaceous sporangia connate and coherent in two ranks on the edges of a simple spike. Sterile segment fleshy, simple in our species; the veins reticulated. Spores copious, sulphur-yellow. (Name from ὄφις, a serpent, and γλῶσσα, tongue.)

1. O. vulgàtum, L. Fronds from a slender rootstock (2–12´ high), mostly solitary; sterile segment sessile near the middle of the plant, ovate or elliptical (1–3´ long); midvein indistinct or none; veins forming small meshes enclosed in larger ones.—Bogs and pastures; not common. July. (Eu.)

Order 133. LYCOPODIÀCEÆ. (Club-Moss Family.)

Low plants, usually of moss-like aspect, with elongated and often much branched stems covered with small lanceolate or subulate, rarely oblong or rounded, persistent entire leaves; the sporangia 1–3-celled, solitary in the axils of the leaves, or on their upper surface, when ripe opening into two or three valves, and shedding the numerous yellow spores, which are all of one kind.—The Order, as here defined, consists mainly of the large genus

1. LYCOPÒDIUM, L. Club-Moss. ([Pl. 21.])

Spore-cases coriaceous, flattened, usually kidney-shaped, 1-celled, 2-valved, mostly by a transverse line round the margin, discharging the subtile spores in the form of a copious sulphur-colored inflammable powder.—Perennials, with evergreen one-nerved leaves, imbricated or crowded in 4–16 ranks. (Name compounded of λύκος, a wolf, and ποῦς, foot, from no obvious resemblance.)

§ 1. Spore-cases in the axils of the ordinary (dark green and shining, rigid, lanceolate, about 8-ranked) leaves.

1. L. Selàgo, L. Stems erect and rigid, dichotomous, forming a level-topped cluster (3–6´ high); leaves uniform, crowded, ascending, glossy, pointed, entire or denticulate; sporangia in the axils of unaltered leaves.—Mountain-tops, Maine to Lake Superior, and northward.—The leaves of this and the next species often bear little gemmæ, with the lower bracts pointed, and the 2–3 uppermost broadly obovate and fleshy, as figured in 1768 by Dillenius. These gemmæ fall to the ground and their axis grows into the stem of a new plant, as specimens collected in 1854 show very plainly. (For their true nature see Sachs' Lehrbuch, Engl. trans., p. 411.)

2. L. lucídulum, Michx. Stems assurgent, less rigid, dichotomous (6–12´ long); leaves pointed, toothed, at first spreading, then deflexed, arranged, in alternate zones of shorter and longer leaves, the shorter leaves more frequently bearing sporangia in their axils; proliferous gemmæ usually abundant.—Cold, damp woods; common northward. Aug.

§ 2. Spore-cases only in the axils of the upper (bracteal) leaves, thus forming a spike.

[*] Leaves of the creeping sterile and of the upright fertile stems or branches and those of the simple spike nearly alike, many-ranked.

3. L. inundàtum, L. Dwarf; creeping sterile stems forking, flaccid; the fertile solitary (1–4´ high), bearing a short thick spike; leaves lanceolate or lance-awl-shaped, acute, soft, spreading, mostly entire, those of the prostrate stems curving upward.—Var. Bigelòvii, Tuckerm., has fertile stems 5–7´ high, its leaves more awl-shaped and pointed, sparser and more upright, often somewhat teeth-bearing.—Sandy bogs, northward, not common; the var., eastern New Eng. to N. J., and southward. Aug. (Eu.)

4. L. alopecuroìdes, L. Stems stout, very densely leafy throughout; the sterile branches recurved-procumbent and creeping; the fertile of the same thickness, 6–20´ high; leaves narrowly linear-awl-shaped, spinulose-pointed, spreading, conspicuously bristle-toothed below the middle; those of the cylindrical spike with long setaceous tips.—Pine-barren swamps, N. J. to Va., and southward. Aug., Sept.—Stems, including the dense leaves, ½´ thick; the comose spike, with its longer spreading leaves, ¾–1´ thick.

[*][*] Leaves (bracts) of the catkin-like spike scale-like, imbricated, yellowish, ovate or heart-shaped, very different from those of the sterile stems and branches.

[+] Spikes sessile (i.e. branches equally leafy to the top), single.

5. L. annótinum, L. Much branched; stems prostrate and creeping (1–4° long); the ascending branches similar (5–8´ high), sparingly forked, the sterile ones making yearly growths from the summit; leaves equal, spreading, in about 5 ranks, rigid, lanceolate, pointed, minutely serrulate (pale green); spike solitary, oblong-cylindrical, thick.—Var. púngens, Spring, is a reduced sub-alpine or mountain form, with shorter and more rigid pointed erectish leaves.—Woods; common northward; the var. on the White Mountains, with intermediate forms around the base. July. (Eu.)

6. L. obscùrum, L. Rootstock cord-like, subterranean, bearing scattered, erect, tree-like stems dividing at the summit into several densely dichotomous spreading branches; leaves linear-lanceolate, decurrent, entire, acute, 6-ranked, those of the two upper and two lower ranks smaller and appressed, the lateral ones incurved spreading; spikes 1–10, erect, mostly sessile; bracts scarious-margined, broadly ovate, abruptly apiculate.—Var. dendroídeum (L. deudroideum, Michx.) has all the leaves alike and incurved spreading.—Moist woods. Aug.—Remarkable for its tree-like appearance.

L. alpìnum, L., or its var. sabinæfòlium, occurs from Labrador to Washington Territory, and is to be expected in northern Maine and Minn. It has slender branches with rigid nearly appressed leaves.

[+][+] Spikes peduncled, i.e. the leaves minute on the fertile branches.

[++] Leaves homogeneous and equal, many-ranked; stems terete.

7. L. clavàtum, L. (Common Club-Moss.) Stems creeping extensively, with similar ascending short and very leafy branches; the fertile terminated by a slender peduncle (4–6´ long), bearing about 2–3 (rarely 1 or 4) linear-cylindrical spikes; leaves linear-awl-shaped, incurved spreading (light green), tipped, as also the bracts, with a fine bristle.—Dry woods; common, especially northward. July. (Eu.)

[++][++] Leaves of two forms, few-ranked; stems or branches flattened.

8. L. Caroliniànum, L. ([Pl. 21.]) Sterile stems and their few short branches entirely creeping (leafless and rooting on the under side), thickly clothed with broadly lanceolate acute and somewhat oblique 1-nerved lateral leaves widely spreading in 2 ranks, and a shorter intermediate row appressed on the upper side; also sending up a slender simple peduncle (2–4´ high, clothed merely with small bract-like and appressed awl-shaped leaves), bearing a single cylindrical spike.—Wet pine-barrens, N. J. to Va., and southward.

9. L. complanàtum, L. (Ground-Pine.) Stems extensively creeping (often subterranean), the erect or ascending branches several times forked above; bushy branchlets crowded, flattened, fan-like and spreading, all clothed with minute imbricated-appressed awl-shaped leaves in 4 ranks, with decurrent-united bases, the lateral rows with somewhat spreading tooth-like tips, those of the upper and under rows smaller, narrower, wholly appressed; peduncle slender, bearing 2–4 cylindrical spikes.—Var. Chamæcyparíssus has narrower, more erect and bushy branches, and the leaves less distinctly dimorphous.—Woods and thickets; common, especially northward. (Eu.)

Order 134. SELAGINELLÀCEÆ.

Leafy plants, terrestrial or rooted in mud, never very large; the stems branching or short and corm-like; the leaves small and 4–6-rowed, or subulate and elongated; sporangia one-celled, solitary, axillary or borne on the upper surface of the leaf at its base and enwrapped in its margins, some containing large spores (macrospores) and others small spores (microspores). The macrospores are in the shape of a low triangular pyramid with a hemispherical base, and marked with elevated ribs along the angles. In germination they develop a minute prothallus which bears archegonia to be fertilized by antherozoids developed from the microspores.

1. Selaginella. Terrestrial; stems slender; leaves small; sporangia minute and axillary.

2. Isoetes. Aquatic or growing in mud; stems corm-like: leaves elongated and rush-like; sporangia very large, enwrapped by the dilated bases of the leaves.

1. SELAGINÉLLA, Beauv. ([Pl. 21.])

Fructification of two kinds, namely, of minute and oblong or globular spore-cases, containing reddish or orange-colored powdery microspores; and of mostly 2-valved tumid larger ones, filled by 3 or 4 (rarely 1–6) much larger globose-angular macrospores; the former usually in the upper and the latter in the lower axils of the leafy 4-ranked sessile spike, but sometimes the two kinds are on opposite sides all along the spike. (Name a diminutive of Selago an ancient name of a Lycopodium, from which this genus is separated, and which the plants greatly resemble in habit and foliage.)

[*] Leaves all alike and uniformly imbricated; those of the spike similar.

1. S. spinòsa, Beauv. Sterile stems prostrate or creeping, small and slender; the fertile thicker, ascending, simple (1–3´ high); leaves lanceolate, acute, spreading, sparsely spinulose-ciliate. (S. selaginoides, Link.)—Wet places, N. H. (Pursh), Mich., Lake Superior, Colorado, and northward; rare.—Leaves larger on the fertile stems, yellowish-green. (Eu.)

2. S. rupéstris, Spring. ([Pl. 21], fig. 1–4.) Much branched in close tufts (1–3´ high); leaves densely appressed-imbricated, linear-lanceolate, convex and with a grooved keel, minutely ciliate, bristle-tipped; those of the strongly quadrangular spike rather broader.—Dry and exposed rocks; very common.—Grayish-green in aspect, resembling a rigid Moss. Very variable farther west and south. (Eu.)

[*][*] Leaves shorter above and below, stipule-like; the lateral larger, 2-ranked.

3. S. àpus, Spring. Stems tufted and prostrate, creeping, much branched, flaccid; leaves pellucid-membranaceous, the larger spreading horizontally, ovate, oblique, mostly obtuse, the smaller appressed, taper-pointed; those of the short spikes nearly similar; larger spore cases copious at the lower part of the spike.—Low, shady places; not rare, especially southward.—A delicate little plant, resembling a Moss or Jungermannia.

2. ISÒETES, L. Quillwort. ([Pl. 21.])

Stem or trunk a fleshy more or less depressed corm, rooting just above its 2-lobed (or in many foreign species 3-lobed) base, above covered with the dilated and imbricated bases of the awl-shaped or linear somewhat quadrangular leaves, which include four air-tubes, intercepted by cross partitions. Sporangia pretty large, orbicular or ovoid, plano-convex, very thin, sessile in the axils of the leaves, and united at the back with their excavated bases (the thin edges of the excavation folding round partly cover them, forming the velum), traversed internally by transverse threads; those of the outer leaves filled with large spherical macrospores, their whitish crustaceous integument marked by one circular, and on the upper surface by three radiating elevated lines (circumscribing a lower hemisphere, and three upper segments which open valve-like in germination); those of the inner leaves filled with very minute and powdery grayish microspores; these are always obliquely oblong and triangular.—Mostly small aquatics, grass-like or rush-like in aspect, some always submerged, others amphibious, a few living in merely moist soil, maturing their fruit in late summer and early autumn, except n. 7 and some forms of n. 6.

This genus is left essentially as it was elaborated for the 5th edition by the late Dr. George Engelmann. The present editor has added to the range of a few species, and given var. robusta of n. 3.

[*] Growing under water, only accidentally or in very dry seasons out of water; leaves without stomata (except in forms of n. 3) and peripherical bast-bundles.

1. I. lacústris, L. ([Pl. 21], fig. 1–5.) Leaves (10–25 in number, 2–6´ long) dark green, rigid; sporangium ovoid or circular, the upper third, or less, covered by the velum, the free part pale and unspotted; both kinds of spores the largest of our species; macrospores (0.32–0.38´´ wide) covered with short and twisted crested ridges, which often anastomose; microspores (0.017–0.020´´ long) smooth.—Mountain lakes, Penn., N. Y., and New Eng. to Lake Superior, and northward, often with n. 3. (Eu.)

2. I. Tuckermàni, Braun. Leaves (10–30, 2–3´ long) very slender, awl shaped, olive-green, the outer recurved; sporangium ovoid or circular, the upper third covered by the velum, the free part sometimes brownish-spotted; macrospores (0.22–0.28´´ wide) on the upper segments covered with parallel and anastomosing ridges, the lower half reticulated; microspores (0.013–0.015´´ long) smooth or very delicately papillose.—Mystic and other ponds near Boston, together with the next (Tuckerman, W. Boott).

3. I. echinóspora, Durieu. Leaves slender, awl-shaped; sporangium ovoid or circular; macrospores (0.20–0.25´´ wide) beset all over with small entire and obtuse or slightly forked spinules. (Eu.)—In this European form, the leaves are very slenderly attenuated (3–4´ long), the upper margin of the sporangium only is covered with the narrow velum, the free part is unspotted, and the slightly papillose microspores are larger (0.015–0.016´´ long).

Var. Braùnii, Engelm. Leaves (15–30 in number, 3–6´ long) dark and often olive-green, straight or commonly recurved, half or two thirds of the sporangium covered by the velum, the free part often with light brown spots; macrospores as in the type; microspores smaller (0.013–0.014´´ long), smooth. (I. Braunii, Durieu.)—Ponds and lakes, New Eng. to N. Y., Penn., Mich., and northward, often with the two preceding.—Frequently with a few stomata, especially in Niagara specimens.

Var. robústa, Engelm. Stouter; leaves (25–70, 5–8´ long) with abundant stomata all over their surface; velum covering about one half of the large spotted sporangium; macrospores 0.18–0.27´´ wide.—Lake Champlain, north end of Isle La Motte (Pringle).

Var. muricàta, Engelm. Leaves (15–30, 6–10´ long) straight or flaccid, bright green; about one half of the almost circular sporangium covered by the velum, unspotted; macrospores (0.22–0.27´´ wide) with shorter and blunter spinules; microspores as in the last variety, or rarely spinulose. (I. muricata, Durieu.)—In some ponds north of Boston (W. Boott).

Var. Boóttii, Engelm. Leaves (12–20, 4–5´ high) awl shaped, stiffly erect, bright green, with stomata; sporangium as in the last; macrospores as in the type, but a little smaller and with very slender spinules. (I. Boottii, Braun, in litt.)—Pond in Woburn, near Boston, partly out of water (W. Boott).

[*][*] Growing partly out of water, either by the pond drying up or by the receding of the ebb tide; leaves with stomata, and in n. 6 and 7 with four or more peripherical bast-bundles.

4. I. saccharàta, Engelm. Leaves (10–15, 2–3´ long) slender, olive-green, curved; sporangium small, ovoid, only the upper edge covered by the velum, nearly unspotted; macrospores (0.20–0.22´´ wide) minutely tuberculate; microspores (0.012´´ long) papillose.—On Wicomico and Nanticoke Rivers, eastern shore of Maryland, between high and low tide (Canby).

5. I. ripària, Engelm. Leaves (15–30, 4–8´ long) slender, deep green, erect; sporangium mostly oblong, upper margin to one third covered by the velum, the free part spotted; macrospores very variable in size (0.22–0.30´´ wide), the upper segments covered by short crested ridges, which on the lower hemisphere run together forming a network; microspores larger than in any other species except n. 1 (0.013–0.016´´ long), mostly somewhat tuberculated.—Gravelly banks of the Delaware, from above Philadelphia to Wilmington, between flood and ebb tide; margins of ponds, Lake Saltonstall, Conn. (Setchell), and northward.—Distinguished from the nearly allied I. lacustris by the stomata of the leaves, the spotted sporangium, the smaller size of the macrospores and their reticulation on the lower half.

6. I. Engelmánni, Braun. Leaves long (25–100, 9–20´ long), light green, erect or at last prostrate, flat on the upper side; sporangium mostly oblong, unspotted, the velum very narrow; macrospores (0.19–0.24´´ wide) covered all over with a coarse honeycomb-like network; microspores (0.012–0.014´´ long) mostly smooth.—Shallow ponds and ditches, from Mass. (near Boston, W. Boott, H. Mann) and Meriden, Conn. (F. W. Hall), to Penn. and Del. and (probably through the Middle States) to Mo.—By far the largest of our species, often mature in July.

Var. grácilis, Engelm. Leaves few (8–12 only, 9–12´ long) and very slender; both kinds of spores nearly as in the type.—Southern New Eng. (Westville, Conn., Setchell) and N. J. (Ennis); entirely submersed!

Var. válida, Engelm. Trunk large and stout (often 1–2´ wide); leaves (50–100, even 200, 18–25´ long) with an elevated ridge on the upper side; sporangium oblong or linear-oblong (4–9´´ long), {1/3}–½ or more covered by the velum; spores very small; macrospores 0.16–0.22´´ wide; microspores 0.011–0.013´´ long, spinulose.—Del. (Canby) and Penn. (Porter). Sept.

7. I. melanópoda, J. Gay. Leaves (15–50, 6–10´ long) very slender, keeled on the back, straight, bright green, usually with dark brown or black shining bases; sporangium mostly oblong, with a very narrow velum, brown or spotted; macrospores very small (0.14–0.18´´ wide), smoothish, or with faint tubercles or ridges; microspores (0.010–0.012´´ long) spinulose.—Shallow ponds, and wet prairies and fields, central and northern Ill. (E. Hall, Vasey), and westward. June, and sometimes again in Nov.—Trunk more spherical and more deeply 2-lobed, and both kinds of spores smaller than in any other of our species; leaves disappearing during the summer heat. Closely approaching the completely terrestrial species of the Mediterranean region.

Order 135. MARSILIÀCEÆ.

Perennial plants rooted in mud, having a slender creeping rhizome and either filiform or 4-parted long-petioled leaves; the somewhat crustaceous several-celled sporocarps borne on peduncles which rise from the rhizome near the leaf-stalks, or are more or less consolidated with the latter, and contain both macrospores and microspores.

1. MARSÌLIA, L. ([Pl. 25.])

Submersed or emersed aquatic plants, with slender creeping rootstocks, sending up elongated petioles, which bear at the apex a whorl of four nervose-veined leaflets, and at or near their base, or sometimes on the rootstock, one or more ovoid sporocarps. These sporocarps or fruit usually have two teeth near the base, and are 2-celled vertically, with many transverse partitions, and split or burst into 2 valves at maturity. The sporocarps have a ring along the edges of the valves, which at length swells up and bears the sausage-shaped compartments from their places. The compartments contain macrosporangia and microsporangia intermixed. (Named for Aloysius Marsili, an early Italian naturalist.)

1. M. quadrifòlia, L. Leaflets broadly obovate-cuneate, glabrous; sporocarps usually 2 or 3 on a short peduncle from near the base of the petioles, pedicelled, glabrous or somewhat hairy, the basal teeth small, obtuse, or the upper one acute.—In water, the leaflets commonly floating on the surface; Bantam Lake, Litchfield, Conn., and now introduced in many places. (Eu.)

2. M. vestìta, Hook. & Grev. Leaflets broadly cuneate, usually hairy, entire (2–7´´ long and broad); petioles 1–4´ long; peduncles free from the petiole; sporocarps solitary, short-peduncled (about 2´´ long), very hairy when young; upper basal tooth of sporocarp longest, acute, straight or curved, lower tooth acute, the sinus between them rounded. (M. mucronata, Braun.)—In swamps which become dry in summer; Iowa and southwestward.

Order 136. SALVINIÀCEÆ.

Floating plants of small size, having a more or less elongated and sometimes branching axis, bearing apparently distichous leaves; sporocarps or conceptacles very soft and thin-walled, two or more on a common stalk, one-celled and having a central, often branched receptacle which bears either macrosporangia containing solitary macrospores, or microsporangia with numerous microspores.

1. AZÓLLA, Lam. ([Pl. 21.])

Small moss-like plants, the stems pinnately branched, covered with minute 2-lobed imbricated leaves, and emitting rootlets on the under side. Conceptacles in pairs beneath the stem; the smaller ones acorn-shaped, containing at the base a single macrospore with a few corpuscles of unknown character above it; the larger ones globose, and having a basal placenta which bears many pedicellate microsporangia which contain masses of microspores.

1. A. Caroliniàna, Willd. Plants somewhat deltoid in outline (4–12´´ broad), much branched; leaves with ovate lobes, the lower lobe reddish, the upper one green with a reddish border; macrospores with three attendant corpuscles, its surface minutely granulate; masses of microspores glochidiate.—Floating on quiet waters, from Lake Ontario westward and southward,—appearing like a reddish hepatic moss.

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Salvínia nàtans, L., was said by Pursh to grow floating on the surface of small lakes in Western New York, and has more recently been said to occur in Missouri. It has oblong-oval floating leaves 4–6´´ long, closely pinnately-veined, which bear conceptacles and branching plumose fibres on their under surface.

Subclass II. CELLULAR ACROGENS, or BRYOPHYTES.

Plants composed of cellular tissue only. Antheridia or archegonia, or both, formed upon the stem or branches of the plant itself, which is developed from the germinating spore usually with the intervention of a filiform or conferva-like prothallus.—Divided into the Musci, or Mosses, and the Hepaticæ.

Division I. HEPÁTICÆ.[1] (Liverworts.)

[Footnote 1: Elaborated for this edition by Prof. L. M. Underwood, of Syracuse, N. Y.]

Plants usually procumbent, consisting of a simple thallus, a thalloid stem, or a leafy axis; leaves when present 2-ranked, with uniform leaf-cells and no midvein; thalloid forms with or without a midvein, smooth or scurfy or scaly beneath and usually with numerous rootlets. Sexual reproduction by antheridia and archegonia, which are immersed in the thallus, or sessile or pedicelled upon it, or borne on a peduncled receptacle. The fertilized archegonium develops into a capsule (sporogonium) closely invested by a calyptra, which ruptures above as the ripened capsule (containing numerous spores and usually elaters) pushes upward. It is also commonly surrounded by a usually double involucre, the inner (often called perianth) more or less tubular, the outer tubular or more often foliaceous, sometimes wholly wanting. Propagation is also effected by offshoots (innovations), runners (flagella), or by gemmæ, which appear at the margin of the leaves or on the surface of the thallus, often in special receptacles.

Order 137. JUNGERMANNIÀCEÆ. Scale-Mosses.

Plant-body a leafy axis or rarely thallose. Capsule borne on a slender often elongated pedicel, splitting at maturity into 4 valves. Elaters mixed with the spores, mostly bispiral (unispiral in n. 1–3, 32, and 33, 1–3-spiral in n. 5 and 28). Antheridia and archegonia diœcious or monœcious, in the latter case either mingled in the same inflorescence, or separated upon the same branch, with the antheridia naked in the axils of the lower leaves, or on separate parts of the same plant. Leaves 2-ranked, incubous (i.e. the apex of each leaf lying on the base of the next above), or succubous (i.e. the apex of each leaf lying under the base of the next above), or sometimes transverse, with frequently a third row of rudimentary leaves beneath the stem.

Artificial Key to the Genera.

§ 1. Plant-body a leafy axis.

[*] Leaves complicate-bilobed (i.e. folded together) or with a small basal lobe.

[+] Lower lobe smaller than the upper.

[++] Root-hairs borne on the stems or underleaves.

1. Frullania. Lower lobe mostly saccate, more or less remote from the stem. Branches intra-axillary, the leaves on either side free.

2. Jubula. Lower lobe saccate; branches lateral, a basal leaf borne partly on the stem, partly on the branch.

3. Lejeunea. Lower lobe incurved, more or less inflated.

5. Porella. Lower lobe ligulate. Perianth triangular, the third or odd angle ventral.

[++][++] Root-hairs rising from the lower lobes.

4. Radula. Perianth compressed. Underleaves none.

[+][+] Upper lobe smaller than the lower, or the two somewhat equal.

[++] Leaves succubous as to their lower lobes.

15. Scapania. Involucral leaves 2; perianth dorsally compressed, the mouth truncate, bilabiate, decurved.

16. Diplophyllum. Involucral leaves few; perianth erect, round, the mouth denticulate.

[++][++] Leaves transverse.

25. Marsupella. Perianth tubular or somewhat compressed. (Compare also Jungermannia § Sphenolobus.)

[*][*] Leaves palmately 3–4- (or many-) cleft.

[+] Divisions numerous, capillary. Plants large, usually in conspicuous mats.

6. Ptilidium. Leaves palmatifid with ciliate margins.

7. Trichocolea. Leaves setaceously multifid.

[+][+] Leaves 3–4-cleft or parted; plants small, mostly inconspicuous.

10. Lepidozia. Leaf-divisions two cells wide or more.

11. Blepharostoma. Leaf-divisions only one cell wide.

[*][*][*] Leaves entire, emarginate, or 2–3-toothed or -lobed.

[+] Leaves closely imbricate on short julaceous stems.

27. Gymnomitrium. Involucre double, the inner shorter.

[+][+] Leaves deeply bilobed.

8. Herberta. Underleaves large. Perianth fusiform on an elongated branch.

12. Cephalozia. Underleaves mostly wanting; perianth mostly triangular on a short branch.

[+][+][+] Leaves incubous, mostly plane or depressed.

9. Bazzania. Leaves mostly 2–3-toothed. Perianth fusiform on a short branch.

14. Kantia. Leaves mostly entire. Perianth fleshy, pendulous, subterranean.

[+][+][+][+] Leaves succubous or transverse.

[++] Underleaves entire or nearly so.

13. Odontoschisma. Involucral leaves numerous, small, incised, those of the stem rounded or retuse.

21. Mylia. Involucral leaves 2, connate at base. Large.

22. Harpanthus. Involucral leaves few, smaller than the semi-vertical emarginate stem-leaves. Small.

24. Jungermannia. Involucral leaves few, mostly larger than the entire or bidentate stem-leaves. Medium-sized or large.

[++][++] Underleaves 2–4-cleft, -parted, or -divided.

17. Geocalyx. Involucre fleshy, saccate, pendent. Leaves bidentate; underleaves 2-cleft.

18. Lophocolea. Fruit terminal on the main stem or a primary branch. Involucral leaves distinct.

19. Chiloscyphus. Fruit on a short lateral branch. Involucral leaves distinct. (See also Jungermannia.)

[++][++][++] Underleaves mostly wanting.

a. Leaves entire or barely retuse.

23. Liochlæna. Involucral leaves distinct, like those of the stem; perianth truncate-depressed at the apex.

26. Nardia. Involucral leaves connate at base and adnate to the perianth.

b. Leaves bidentate or bilobed, rarely 3-lobed.

12. Cephalozia. Branches all from beneath. Perianth on a short branch, mostly trigonal with the odd angle beneath.

24. Jungermannia. Simple or branching laterally. Perianth terminal, mostly laterally compressed.

c. Leaves mostly spinulose or dentate.

20. Plagiochila. Involucral leaves large; perianth laterally compressed.

§ 2. Plant-body pseudo-foliaceous with succubous leaf-like lobes.

28. Fossombronia. Perianth large, campanulate.

§ 3. Plant-body a thallus.

[*] Thallus with a distinct costa.

29. Pallavicinia. Thallus 3–6´´ wide, mostly simple, the margins sinuate or undulate. Perianth tubular, at length dorsal.

30. Blasia. Thallus 3–6´´ wide, lobed, dichotomous, or radiate, the margins pinnatifid-sinuate.

32. Metzgeria. Thallus narrow (1–2´´), ciliate at the margins or on one or both sides.

[*][*] Thallus with an inconspicuous costa or none.

33. Aneura. Thallus rather narrow, mostly palmately or pinnately lobed. Sporogonium rising from the under side near the margin.

31. Pellia. Thallus wider, mostly simple or forked. Sporogonium rising from the upper surface.

1. FRULLÀNIA, Raddi. ([Pl. 24.])

Leaves incubous, complicate-bilobed, the lower lobe usually inflated, helmet- or club-shaped; underleaves bifid, rarely entire, with basal rootlets. Diœcious or monœcious. Fruit terminal on the branches. Involucral leaves 2 or 4, larger than the stem-leaves; perianth 3–4-angled, mucronate. Calyptra pyriform, fleshy. Capsule globose, the lower third solid. Elaters truncate at each end, unispiral, adherent to the valves. Spores large, reddish, minutely muricate. Antheridia most often on a short branch, globose-oblong or cylindric. Archegonia 2–4, long-styled. (Named for Leonardo Frullani, an Italian Minister of State.)

§ 1. TRACHYCÓLEA. Perianth triangular in section, rough with tubercles or scales, or villous; lower leaf-lobe helmet-shaped, truncate at base.

[*] Lower leaf-lobe about three fourths the size of the upper.

1. F. Oakesiàna, Aust. Stems widely branching; fertile branches short; leaves obliquely orbicular, loosely imbricate, the lower lobe rotund, contiguous to the stem; underleaves ovate-rotund or subobovate, little wider than the stem, bifid; involucral leaves more or less connate, equally bilobed, the lobes entire, obtuse; perianth small, subobovate-pyriform, smooth or 1–7-nerved or alate both sides.—White Mts., on stunted spruce and birch trees.

[*][*] Lower leaf-lobe much smaller than the upper.

[+] Underleaves scarcely wider than the stem, ovate, bifid, the divisions entire, acute; perianth 1-carinate or smooth, except in n. 2; stems creeping.

2. F. Virgínica, Lehm. Stems short, irregularly branching; leaves crowded, ovate, entire, somewhat concave, the lower lobes sometimes expanded into a lanceolate lamina; underleaves round-ovate, bifid, twice the width of the stem; perianth compressed-pyriform, tuberculate, 2–4-carinate dorsally, 4-carinate ventrally.—On bark of trees, rarely on rocks; common.

3. F. Eboracénsis, Lehm. Branches clustered; leaves loose, imbricate on the branches, round-ovate, entire; perianth pyriform, slightly compressed and repand, smooth, obscurely carinate beneath and gibbous toward the apex. (F. saxatilis, Lindenb.)—On trees and rocks; common northward.

4. F. Pennsylvánica, Steph. Stems dichotomous; leaves imbricate, flat, ovate, mucronate or rarely obtuse, entire; lower lobe marginal, large, round-cucullate; underleaves broadly ovate, deeply parted, the divisions long-acuminate; diœcious; antheridial spikes on short lateral branches, elongated; lobes of the involucral leaves acuminate, much narrowed at base, and the large underleaves carinate-concave, deeply parted, their apiculate divisions entire or toothed.—Shaded rocks, Stony Creek, Carbon Co., Penn. (Rau). Known only from the original description.

5. F. saxícola, Aust. Stems numerous, widely branching; leaves orbicular, scarcely oblique, flat; lower lobe near the stem, small, or rarely larger and round-galeate; underleaves scarcely wider than the stem, subovate, bifid; perianth broadly oblong, bowl-shaped with very short mouth, papillose, abruptly broad-carinate beneath, 1–many-nerved each side of the keel, 2-angled.—Sloping dry trap rocks, Closter, N. J. (Austin).

[+][+] Underleaves 2–3 times wider than the stem, round or subquadrate, bifid, the divisions blunt or truncate.

[++] Leaves lax, rather distant; lower lobe mostly expanded, ovate-lanceolate.

6. F. æolòtis, Nees. Procumbent, irregularly branched or subpinnate; leaves semi-vertical, subsquarrose, obliquely cordate, the lower lobe expanded; underleaves ovate, acutely bifid, the upper margin angular-dentate or entire; sporogonium unknown.—On trees and rocks, chiefly in mountain regions.

[++][++] Leaves close-imbricate; lower lobe galeate, seldom expanded except on terminal leaves.

7. F. squarròsa, Nees. Decumbent, pinnately branching, the short fertile branch lateral; leaves subvertical, suborbicular, obtuse, entire; lower lobe obovate-cucullate or galeate, subappressed; underleaves cordate or rounded, sinuate-subdentate, slightly bifid; perianth oblong, triquetrous, convex dorsally, strongly keeled ventrally.—On rocks and trees, N. Y. to Ohio, and southward; rather common.

8. F. plàna, Sulliv. Procumbent, widely branching or subpinnate; leaves orbicular, subimbricate; lower lobe very small, as broad as long, close to the stem; underleaves rather large, flat, rounded, slightly bifid; monœcious; perianth oblong-oval or subobovate, triquetrous, dorsally sulcate, acutely keeled ventrally; antheridial spikes globose.—Shaded rocks, N. Y. and N. J. to E. Tenn.

9. F. dilatàta, Nees. Loosely and widely pinnate; leaves round, entire, opaque; lower lobe subrounded, cucullate, close to the stem; underleaves subquadrate, toothed at the anterior angles; involucral leaves with 2 or 3 entire lobes; perianth tuberculate, retuse.—Rocks and trunks of trees; rather common. (Eu.)

§ 2. THYOPSIÉLLA. Perianth smooth; leaves semicordate at base (marked by a central moniliform row of cells, or sometimes in n. 12 by a few scattered large cells); lower lobe near the stem (except in n. 11), cylindric-saccate, mostly erect; underleaves round-oval, the margin entire, recurved; diœcious.

[*] Leaves orbicular.

10. F. Asagrayàna, Mont. ([Pl. 24.]) Creeping, simply pinnate; leaves concave, obtuse, decurved; lower lobe oblong-clavate, emarginate at base; underleaves oblong, flat, 2-cleft, the sinus obtuse; involucral leaves unequally 2-cleft, the dorsal segment oblong, pointed, nearly entire, the ventral subulate; perianth pyriform, 3-sided, obtusely keeled beneath. (F. Grayana of authors.)—Rocks and bark of coniferous trees; frequent.

11. F. Tamarísci, Nees. Bipinnately branching, somewhat rigid; leaves obtuse, mucronately acute or subacuminate, decurved, entire; lower lobe distant from the stem, oval or oblong; underleaves quadrate-ovate or obovate, emarginate, the margin revolute; involucral leaves bifid, serrulate; perianth oblong, sulcate dorsally, obtusely keeled ventrally.—N. Eng. and southward; rare. (Eu.)

[*][*] Leaves oblong from a narrowed base.

12. F. fragilifòlia, Tayl. Procumbent, subpinnate, the alternate flattened branches subremote; leaves subimbricate, ascending, recurved, entire; lower lobe oblong-galeate; underleaves round-obovate, flat, appressed, bifid, the margins entire or angled; perianth obovate-cordate, concave dorsally, keeled ventrally; involucral leaves subequally lobed, obtusely few-toothed. (F. polysticta, Mont. F. Sullivantiæ, Aust.)—On trees in a cedar swamp, Urbana, Ohio (Sullivant). (Eu.)

2. JÙBULA, Dumort. ([Pl. 25.])

Characters nearly as in Frullania. Leaves large and flat, an axillary one at the base of each branch without a lower lobe. Calyptra turnip-shaped, abruptly globose above. Monœcious, with 2 antheridia in each leaf of a spike-like branch, and the archegonia mostly solitary. (Name from juba, a mane, alluding to the persistent elaters.)

1. J. Hutchínsiæ, Dumort., var. Sullivántii, Spruce. Subdichotomously branching; leaves dark olive-green, subimbricate, obliquely ovate, acute, entire or subrepand; lower lobe saccate, rather remote from the stem, not spurred as in the European form; underleaves roundish, serrate or entire; involucral leaves bifid, serrate; perianth triangular-obpyriform. (Frullania Hutchinsiæ, Nees, in part.)—Wet rocks, N. Eng. to S. C.; more common in the mountains.

3. LEJEÙNEA, Libert. ([Pl. 24.])

Leaves decurrent at the folds, the lower lobe incurved and ventricose; underleaves usually present, entire or bifid. Archegonium with a slender persistent style, solitary on a usually very short branch; the perianth free from the involucral leaves, oval or oblong, terete or angular, variously carinate, cristate, or ciliate. Capsule globose, 4-cleft to the middle, the valves recurved. Spores large (40–50 µ broad), globose or oblong, tuberculate. Antheridia at the base of ordinary leaves or in the axils of the leaves of a spike-like branch.—Otherwise as Frullania. (Named for A.-L.-S. Lejeune, a French botanist.)

[*] Underleaves entire.

1. L. clypeàta, Sulliv. ([Pl. 24.]) Stems procumbent, somewhat pinnately branched, ¾–1´ long; leaves whitish-green, round-ovate, cellular-crenulate, deflexed; lower lobe flat, oblong-quadrate; underleaves round-quadrate; monœcious; involucral leaves larger than those of the stem, the perianth round-obovate, 2–3-carinate dorsally, 1-carinate ventrally, the keels rough. (L. calyculata, Tayl.)—On rocks and trees; common south and westward.

[*][*] Underleaves bifid; leaves entire.

2. L. serpyllifòlia, Libert, var. Americàna, Lindb. Stems long, somewhat branching, pale, pellucid and fragile; leaves rather remote, flat, opening from a basilar sac, scarcely decurved, obliquely roundish-ovate, obtuse, often slightly repand; underleaves about half as large, round-oval with a broad obtuse sinus and acute lobes; monœcious; the obovate-clavate perianth on a lateral branch. (L. cavifolia, Aust.)—On cedars, etc., Catskill Mts. (Cleve), Belleville, Ont. (Macoun), and southward; rather common.

3. L. lùcens, Tayl. Whitish, filiform, pinnately branched; leaves remote, rarely subimbricate, obliquely ovate-triangular, rounded or obtuse, semi-cordate at base; lower lobe ovoid, acute or apiculate; underleaves ½ as large as the lateral, round-oval, deeply bifid, the lobes broad-subulate; diœcious; involucral leaves rather longer, with lanceolate lobes; perianth scarcely emersed, broadly pyriform, 5-carinate. (L. cucullata, Sulliv.; not Nees.)—Near Cincinnati; moist rocks, Alleghany Mts. and southward (Sullivant). Minute and flaccid.

[*][*][*] Underleaves obsolete; leaves muriculate-denticulate.

4. L. calcàrea, Libert. Very minute; stems slender, loosely branching; leaves ovate, falcate-decurved, sinuate-complicate at base; monœcious; involucral leaves bifid, the divisions entire; perianth on a very short lateral branch, pyriform-clavate, acutely 5-angled, the margin echinate-muriculate. (L. echinata, Tayl.)—On rocks and roots of trees; rather common. (Eu.)

4. RÁDULA, Dumort. ([Pl. 24.])

Leaves large, complicate-bilobed, incubous; lower lobe small, bearing root-hairs; underleaves none. Diœcious, rarely monœcious. Fruit usually terminal. Involucral leaves 2, slightly smaller than the cauline, 2-lobed; perianth tubular, compressed or nearly terete, truncate, entire or crenate. Calyptra pyriform, persistent. Capsule oval-cylindric. Elaters slender, free. Spores large, globose, minutely tuberculate. Antheridia in the ventricose bases of spicate leaves. (Radula, a scraper or spatula, in allusion to the form of the perianth.)

[*] Lower lobe subquadrate, barely incumbent on the stem.

1. R. complanàta, Dumort. Creeping, widely subpinnately branching; leaves imbricate, spreading, rounded, the lower lobe obtuse or acute; monœcious; perianth obconic, compressed, the mouth entire, truncate; antheridia in the bases of 2–3 pairs of strongly imbricate tumid leaves.—On rocks aud roots of trees; common. (Eu.)

2. R. obcónica, Sulliv. ([Pl. 24.]) Smaller, indeterminately branched; leaves somewhat remote, round-obovate, convex; monœcious; perianth clavate-obconic, obliquely truncate; antheridia axillary on short lateral branches rising near the terminal involucre.—On trees in cedar swamps, N. J. to Ohio.

[*][*] Lower lobe small, rounded, more or less transversely adnate.

3. R. tènax, Lindb. Stems brownish-green, rigid, tenacious; leaves remote, scarcely decurrent, obliquely elliptic-ovate, opaque, the cells round and strongly chlorophyllose; diœcious; the antheridial spike lateral below the keel of a leaf, long, linear, somewhat obtuse. (R. pallens, Sulliv.; not Gottsche.)—On rotten trunks, in the Catskill Mts., and southward, especially in the mountains.

5. PORÉLLA, Dill. ([Pl. 24.])

Leaves large, incubous, complicate-bilobed; lower lobe ligulate, suberect; underleaves similar, decurrent at base, the apex entire. Diœcious. Fruit on a short lateral branch. Involucral leaves usually 4, 2-lobed, the margin ciliate or denticulate; perianth somewhat oval, compressed, bilabiate, incised or entire. Calyptra globose, persistent. Capsule globose, reddish, short-stalked. Elaters very numerous, 2–3-spiral, free. Spores large, rough. Antheridia solitary in the saccate bases of leaves, crowded in short spikes. (Name a diminutive of porus, an opening.)

[*] Leaves more or less remote; stems bipinnate.

1. P. pinnàta, L. Stems irregularly pinnate, fastigiate at the ends; leaves scarcely incubous, ovate-oblong, the rounded apex sometimes slightly decurved; lower lobe minute, flat, oblong, obtuse, as long but not half as wide as the flat, entire, ovate-rectangular, scarcely decurrent underleaves. (Madotheca Porella, Nees.)—On rocks and trees subject to inundation; common. (Eu.)

[*][*] Leaves mostly closely imbricate; stems mostly simply pinnate (or bipinnate in n. 2).

2. P. platyphýlla, Lindb. ([Pl. 24.]) Yellowish or fuscous-green; stems irregularly pinnate, often fastigiate at the ends; leaves obliquely ovate, more or less concave at base and the rounded upper margin curved upward aud undulate, mostly entire; lower lobe obliquely ovate, the margin strongly recurved, with an acute tooth at base; underleaves semicircular, with strongly reflexed margins. (Madotheca platyphylla, Dumort.)—On rocks and trees; common eastward. (Eu.)

3. P. Thùja, Lindb. Fuscous-green or blackish, somewhat regularly pinnate; leaves convex, closely appressed, obliquely round-ovate, the rounded apex decurved, more or less denticulate; lower lobe oblong, obtuse, with an acute tooth at base, longer but narrower than the quadrate underleaves, both with strongly recurved sparsely denticulate margins. (Madotheca Thuja, Dumort.)—On rocks and trees; more common westward. (Eu.)

4. P. dentàta, Lindb. Mostly fuscous-green, irregularly pinnate or subdichotomous; leaves more remote on the branches, obliquely round-ovate, the rounded summit slightly decurved, more or less denticulate; lower lobe decurrent, twisted, obliquely ovate, acute, with recurved undulate denticulate margin and a large acute tooth at base; underleaves twice as wide as the lower lobes, quadrate-oval, the undulate reflexed margin dentate, especially near the base. (Madotheca rivularis, Nees.)—Shaded rocks, Yellow Springs, Ohio (Sullivant). (Eu.)

5. P. Sullivántii, Underw. Stems strongly decurved at the ends in drying; leaves suberect, the straight ventral margin strongly involute toward the apex; cells large, punctate-stelliform; perianth broadly keeled beneath, the keel 2-angled. (Madotheca Sullivantii, Aust.)—Alleghany Mts. (Sullivant); rare.

6. PTILÍDIUM, Nees. ([Pl. 24.])

Leaves incubous, complicate-bilobed, each lobe divided and lacerately ciliate; underleaves 4–5-lobed, ciliate. Diœcious. Fruit terminating short branches. Involucral leaves 2–4, 4-cleft; perianth terete, obovate, the mouth connivent, plicate, denticulate. Calyptra pyriform, coriaceous. Capsule ovate. Spores globose. Antheridia in the base of closely imbricated leaves. (Name a diminutive of πτίλον, a feather, from the fringed foliage.)

1. P. ciliàre, Nees. Stems crowded, subpinnate; fringes of the foliage long-setaceous. (Blepharozia ciliaris, Dumort.)—On rotten logs and stumps; common. (Eu.)

7. TRICHOCÓLEA, Dumort. ([Pl. 24.])

Leaves succubous, 4–5-divided, and with the underleaves setaceously fringed. Diœcious. Fruit terminal, or axillary from the growth of innovations. Involucral leaves coalescent into an oblong truncate hairy tube, blended in our species with the calyptra; perianth none. Capsule oblong, its pedicel bulbous at base. Elaters free. Antheridia large, in the axils of leaves on terminal branches. (Name from θρίξ, hair, and κολεός, a sheath, from the hairy involucre.)

1. T. tomentélla, Dumort. Stems pinnately decompound, densely tufted, glaucous, 2–6´ long; leaves nearly uniform; underleaves subquadrate, as wide as the stem.—Among mosses in swamps; common. (Eu.)

T. Biddlecòmiæ, Aust., very imperfectly described from specimens collected in Urbana, Ohio, is said to be simply and rather distantly pinnate.

8. HERBÉRTA, S. F. Gray. ([Pl. 24.])

Leaves large, incubous or nearly transverse, narrow, 3-ranked, the underleaves being scarcely smaller, cleft to or below the middle, the lobes acute. Diœcious. Fruit terminal on a long branch. Involucral leaves numerous, equitant; perianth ovate-subulate or narrowly fusiform, 3-angled, deeply 6–8-lobed. Calyptra small, obovate, deeply trifid. Capsule large, globose. Elaters free. Spores large, muriculate. Antheridia in the bases of leaves of a short terminal spike. (Named for William Herbert, an English botanist.)

1. H. adúnca, S. F. Gray. Stems long and slender, erect, brownish, nearly simple; leaves and underleaves almost alike, curved and one-sided, the lobes lanceolate. (Sendtnera juniperina, Sulliv.; not Nees.)—On rocks, Greenwood Mts., N. J., Catskill Mts., N. Y., and probably northward. (Eu.)

9. BAZZÀNIA, S. F. Gray. ([Pl. 24.])

Leaves incubous, oblique, decurved, mostly truncate-tridentate; underleaves wider than the stem, mostly 3–4-toothed or crenate. Diœcious. Fruit on a short branch from the axil of an underleaf. Involucral leaves much imbricate, concave, orbicular or ovate, incised at the apex; perianth ovate-subulate or fusiform, somewhat 3-keeled. Calyptra pyriform or cylindric-oblong. Capsule oblong. Antheridial spikes from the axils of underleaves. (Named for M. Bazzani, an Italian Professor of Anatomy.)

1. B. trilobàta, S. F. Gray. ([Pl. 24.]) Creeping, dichotomous, proliferous; leaves ovate, the broad apex acutely 3-toothed; underleaves roundish-quadrangular, spreading, 4–6-toothed above; perianth curved, cylindric, plicate at the narrow apex and 3-toothed. (Mastigobryum trilobatum, Nees. M. tridenticulatum, Lindenb.)—Ravines, wet woods and swamps; common and variable. (Eu.)

2. B. defléxa, Underw. Stems forked or alternately branched; leaves strongly deflexed, cordate-ovate or ovate-oblong, falcate, the upper margin arcuate, the narrow apex 2–3-toothed or entire; underleaves roundish-quadrate, the upper margin bifid, crenate, or entire; perianth cylindric, arcuate, plicate above and denticulate. (Mastigobryum deflexum, Nees.)—On rocks in the higher mountains eastward. (Eu.)

10. LEPIDÒZIA, Dumort. ([Pl. 24.])

Leaves small, incubous, palmately 2–4-cleft or -parted; underleaves similar, often smaller. Diœcious or rarely monœcious. Fruit terminal on short branches from the under side of the stem. Involucral leaves small, appressed, concave, 2–4-cleft; perianth elongated, ovate-subulate or narrowly fusiform, obtusely triangular above, entire or denticulate. Calyptra included, pyriform or oblong. Capsule oblong-cylindric. Spores minute, smooth or roughish. Antheridia large, pedicelled, solitary in the axils of 2-cleft spicate leaves. (Name from λεπίς, a scale, and ὄζος, a shoot, for the scale-like foliage.)

1. L. réptans, Dumort. ([Pl. 24.]) Creeping, pinnately compound, the branches often flagellate; leaves decurved, subquadrate, 3–4-cleft; involucral leaves ovate, truncate, unequally 4-toothed; perianth incurved, dentate.—On the ground and rotten wood, N. J., and common northward. (Eu.)

2. L. setàcea, Mitt. Leaves deeply 2–3-cleft or -parted, incurved, the lobes subulate, formed of a somewhat double series of cells; underleaves similar; perianth ciliate. (Jungermannia setacea, Web.)—On the ground and rotten wood; common. Resembling the next in its leaves, but smaller and brownish. (Eu.)

11. BLEPHARÓSTOMA, Dumort. ([Pl. 25.])

Leaves transverse or slightly incubous, 3–4-parted, the divisions capillary; underleaves smaller, mostly 2–3-parted. Diœcious or monœcious. Fruit terminal. Involucral leaves numerous, verticillate, deeply 4-cleft; perianth exserted, pyriform-cylindric, laciniate. Calyptra short, oblong, bilabiate. Capsule cylindric-oblong. Elaters large, very obtuse. Spores large, smooth. Antheridia solitary in the axils of leaf-like bracts. (Name from βλέφαρον, an eyelid, and στόμα, mouth, in allusion to the fringed orifice of the perianth.)

1. B. trichophýllum, Dumort. Flaccid, branched, creeping; leaf-divisions straight, spreading, each composed of a single row of cells; perianth ovate-cylindric. (Jungermannia trichophylla, L.)—On the ground and rotten wood. Minute, light green. (Eu.)

12. CEPHALÒZIA, Dumort. ([Pl. 23.])

Leaves mostly succubous, chiefly 2-lobed, the margins uniformly plane or subincurved; underleaves smaller, often wanting except on fruiting branches. Branches from the under side of the stem. Monœcious or diœcious. Involucral leaves numerous, capitate, 3-ranked, usually 2-lobed; perianth long, triangular-prismatic, the constricted mouth variously dentate. Calyptra small. Capsule somewhat oblong. Elaters free. Spores minute. Antheridia in the base of inflated spicate leaves. (Name from κεφαλή, head, and ὄζος, bud, for the capitate involucre.)

§ 1. CEPHALOZIA proper. Perianth more or less 3-angled or 3-carinate; leaf-cells large (mostly 25–50 µ broad); plants mostly medium-sized.

[*] Underleaves rarely present except on fruiting branches.

1. C. Virginiàna, Spruce. Without runners, usually pale; leaves small, obliquely round-ovate, acutely 2-lobed nearly to the middle; cells quadrate-hexagonal, opaque; diœcious, rarely monœcious; involucral leaves round-quadrate, with slender acuminate lobes; perianth large, widest above the middle, unequally ciliolate; capsule large, long-exserted; antheridial spike long. (C. catenulata of authors; not Huebn.)—On rotten wood or swampy ground, N. Eng. to Va., and southward.

2. C. multiflòra, Spruce. ([Pl. 23.]) Often subpinnate, without runners, pale green; leaves small, round-rhombic, decurrent, bifid {1/3} their length; cells quadrate-hexagonal, pellucid; diœcious; inner involucral leaves 3–4 times as long as the outer; perianth linear-fusiform, 3-plaited when young, triangular only above when mature, ciliate or toothed, fleshy; calyptra fleshy, oval-globose; capsule rather short-pedicelled; spores cinnamon-color.—On the ground and rotten wood; common. (Eu.)

3. C. pléniceps, Underw. Stems very short, branching, densely cespitose, pale green or whitish; leaves thick, orbicular, strongly concave, subclasping but not decurrent, bifid {1/3} their length, the acute lobes incurved and strongly connivent; involucral leaves oblong, palmately 2–4-cleft, the ventral like the underleaves; perianth large, oblong-cylindric, obtusely angled, the plicate mouth denticulate. (Jungermannia pleniceps, Aust.)—Among Sphagnum in the White Mts. (Oakes).

4. C. bicuspidàta, Dumort. Prostrate or assurgent, cespitose, usually greenish or reddish, with runners; lower leaves small and distant, the upper larger, round-ovate, cleft nearly to the middle, the lobes ovate-lanceolate and acute, the lower lobe narrower and acuminate; cells large, pellucid; monœcious; involucral leaves about 3 pairs, the innermost nearly three times as long as the outer, cleft ½ their length; perianth four times as long as the leaves, linear-prismatic or fusiform, thin, denticulate or ciliate; capsule cylindric-oblong; spores purple. (Jungermannia bicuspidata, L.)—On the ground, mountains of N. Eng., N. Y., and N. J. (Eu.)

5. C. curvifòlia, Dumort. Slender, rarely forked, without runners, greenish, reddish, or often purple; leaves imbricate, ascending, obovate, concave, semicordate at base, lunately bifid below the middle, the lobes incurved or hooked; cells small, quadrate; monœcious or diœcious; involucral leaves complicate, the lobes subovate, spinulose-denticulate; perianth large, rose-purple, triquetrous, the wide mouth ciliate; calyptra thin; capsule oblong-globose. (Jungermannia curvifolia, Dicks.)—On rotten logs in swamps, etc.; common. (Eu.)

[*][*] Underleaves usually present; leaves rarely subimbricate.

6. C. flùitans, Spruce. Stems 2–3´ long, loosely creeping, with short thick runners; leaves large, ovate-oblong, lobed to near the middle, the lower lobe larger, lanceolate, obtuse; cells large, mostly hexagonal; underleaves linear, appressed; diœcious; involucral leaves cleft to the middle; perianth oval-cylindric, nearly entire; calyptra short, pyriform; capsule oblong; spores small, minutely tuberculate; antheridia globose, pedicelled, solitary in the axils.—In bogs, on mosses or partly floating; rare. (Eu.)

§ 2. CEPHALOZIÉLLA. Perianth 3–6-angled; leaf-cells small (14–20 µ broad); plants small, often minute; underleaves present in n. 9.

7. C. divaricàta, Dumort. Sparingly branched, without runners; leaves very small, cuneate or round-quadrate, the ovate-triangular lobes acute; cells pellucid or subopaque; involucral leaves larger, the lobes acute, denticulate; perianth linear or narrowly fusiform, prismatic, denticulate or subentire; capsule oblong-globose, long-exserted. (Jungermannia divaricata, Smith.)—Dry rocks and sand, pine barrens of N. J., and northward. (Eu.)

8. C. Macoùnii, Aust. Slender, much branched, dark green; leaves scarcely broader than the stem, wide-spreading, bifid with a broad or lunate sinus, the broad-subulate lobes mostly acute; cells subquadrate, somewhat pellucid; diœcious; involucral leaves appressed, 2–3-lobed, irregularly spinulose; perianth small, whitish, obovate or ovate-fusiform, obtusely 3-angled, setulose or ciliate.—Rotten logs, mountains of N. Eng., and northward (Austin, Macoun).

9. C. Sullivántii, Aust. Stems 3–6´´ long, fleshy, rootlets numerous; fertile branches suberect, clavate; leaves imbricate, often narrower than the stem, subquadrate-ovate, more or less serrate, the sinus and lobes subacute; diœcious; involucral leaves 3, erect, free; perianth broadly oval or subobovate, obtusely and sparingly angled, the apex slightly plicate, the mouth connivent, dentate, sometimes narrowly scarious; capsule oval.—On rotten wood, N. J., Ohio, and Ill.; rare. Our smallest species.

13. ODONTOSCHÍSMA, Dumort. ([Pl. 24.])

Leaves succubous, ovate or roundish, entire or retuse, rarely bidentate; underleaves minute, sometimes obscure or wanting. Diœcious or sometimes monœcious. Fruit terminal on a short branch from the lower side of the stem. Involucral leaves few, 3-ranked, bifid or rarely 3–4-cleft; perianth large, triangular-fusiform, ciliate or dentate. Calyptra membranous. Capsule cylindric-oblong. Antheridia in small whitish spikes on the under side of the stem. (Name from ὀδούς, a tooth, and σχίσμα, a cleft, alluding to the perianth.)

1. O. Sphágni, Dumort. ([Pl. 24.]) Leaves spreading or ascending, ovate, rounded or oblong, entire or retuse, subconcave; underleaves mostly wanting; perianth 3–6 times longer than the leaves, subulate-fusiform, laciniate or ciliate. (Sphagnœcetis communis, Nees.)—Among mosses, N. J. to Ill., and southward. (Eu.)

2. O. denudàta, Lindb. Stems densely rooting, somewhat leafless at base, flagellate, branching above; leaves spreading, broadly ovate, entire; underleaves broadly oval, entire or subdenticulate; perianth close-connivent above, at length bursting irregularly.—On rotten wood, Canada to Ohio, and south along the mountains. (Eu.)

14. KÁNTIA, S. F. Gray. ([Pl. 24.])

Leaves large, incubous, flat or convex, entire or retuse; underleaves small, roundish, the apex entire, retuse or bifid. Diœcious or monœcious. Involucre pendulous, subterranean, clavate or subcylindric, fleshy, hairy, attached to the stem by one side of its mouth. Calyptra membranous, partly adnate to the involucre. Capsule cylindric, the valves spirally twisted. Spores minute, roughish. Antheridia solitary in the reduced leaves of short lateral branches. (Name from J. Kant, a physician at The Hague.)

1. K. Trichómanis, S. F. Gray. ([Pl. 24.]) Creeping, without ventral runners; leaves pale green, imbricate, spreading, roundish-ovate, obtuse. (Calypogeia Trichomanis, Corda.)—On the ground and rotten logs; very common. (Eu.)—Var. rivulàris, Aust. Leaves dusky green or blackish, more scattered, flaccid; cells large. N. J. (Austin.)—Var. ténuis, Aust. Very slender, innovate-branching; leaves smaller, especially above, dimidiate-ovate or subfalcate, subdecurrent. Southern N. J. (Austin).

2. K. Sullivántii, Underw. Prostrate, with ventral runners; leaves flat, subcontiguous or imbricate, obliquely round-ovate, minutely 2-toothed with a lunulate sinus, abruptly decurrent; cells large, uniform; underleaves minute, the upper orbicular, bifid, the lower twice 2-lobed, the primary lobes round-quadrate, divaricate, the secondary ovate or subulate. (Calypogeia Sullivantii, Aust.)—Delaware Water Gap, N. J. (Austin).

15. SCAPÀNIA, Dumort. ([Pl. 24.])

Leaves complicate-bilobed, the upper lobe smaller, the lower succubous; margins entire or dentate or ciliate; underleaves none. Diœcious. Fruit terminal. Involucral leaves like the cauline but more equally lobed; perianth obovate, dorsally compressed, bilabiate, the mouth truncate, entire or toothed, decurved. Capsule ovate. Elaters long, attached to the middle of the valves. Antheridia 3–20, in the axils of small saccate leaves, which are scarcely imbricate or crowded into terminal heads. (Name from σκαπάνιον, a shovel, from the form of the perianth.)

[*] Leaf-lobes somewhat equal.

1. S. subalpìna, Dumort. Leaves equidistant, imbricate, cleft nearly to the middle, the roundish obtuse lobes denticulate on the outer margin; perianth much exceeding the involucral leaves, obovate from a narrow base, denticulate.—Mountains of N. Eng. (Oakes, Austin); L. Superior (Gillman, Macoun). (Eu.)

2. S. glaucocéphala, Aust. Stems short, cespitose, creeping or ascending, subsimple, with numerous offshoots; leaf-lobes broadly ovate, entire, mostly obtuse and apiculate; involucral leaves sometimes denticulate; perianth small, subcuneate, entire. (Jungermannia glaucocephala, Tayl.; S. Peckii, Aust.)—On rotten wood, N. Eng. to N. Y. and Canada.

[*][*] Lower lobe about twice the size of the upper, except near the summit.

[+] Leaves broader than long; upper lobes rounded or blunt.

3. S. undulàta, Dumort. ([Pl. 24.]) Ascending or erect, slightly branched; leaves lax, spreading, entire or ciliate-denticulate, the lobes round-trapezoidal, equal at the summit of the stem; perianth oblong-incurved, nearly entire, twice as long as the outer involucre.—In woods, damp meadows, and rills; common, especially in mountain districts.—Var. purpùrea, Nees; a form with long lax stems and rose-colored or purplish leaves. (Eu.)

4. S. irrígua, Dumort. Creeping; leaves somewhat rigid, repand, deeply lobed; lobes rounded, submucronate, the lower appressed, the upper convex with incurved apex; perianth ovate, denticulate. (S. compacta, var. irrigua, Aust.)—Wet places, N. J., Catskill Mts., mountains of N. Eng., and northward. (Eu.)

[+][+] Leaves longer than broad; upper lobes more or less acute.

5. S. nemoròsa, Dumort. Rather stout, flexuose, creeping at base; leaves rather distant, decurrent on both sides, ciliate-dentate, the lower lobe obovate, obtuse, slightly convex, the upper cordate, acute, concave; perianth densely ciliate; capsule large, roundish-ovate, reddish-brown. (S. breviflora, Tayl.)—On rocks, etc., in swamps and rills; common and variable. (Eu.)

6. S. Oakèsii, Aust. Leaves obovate, somewhat spreading, often deflexed, closely complicate, convex, the lower lobe coarsely dentate, and with deep purple spur-like teeth on the keel, the upper roundish and less dentate; perianth usually dentate.—White Mts. (Oakes, Austin).

[*][*][*] Lower lobes 3–4 times the size of the upper.

7. S. exsécta, Aust. Ascending; leaves subcomplicate, entire, the lower lobe ovate, acute or bidentate, concave, the upper small and tooth-like; involucral leaves 3–5-cleft; perianth oblong, obtuse, plicate. (Jungermannia exsecta, Schmidel.)—High mountains, far northward; rare.—Perhaps better retained in Jungermannia. (Eu.)

8. S. umbròsa, Dumort. Stems short, decumbent, slightly branched; leaf-lobes ovate, acute, serrate; perianth incurved, naked at the mouth.—White Mts.; rare.—The tips of the shoots are frequently covered with a dark mass of gemmæ. (Eu.)

16. DIPLOPHÝLLUM, Dumort. ([Pl. 25.])

Leaves rather narrow, complicate-bilobed, the lobes subequal or the upper smaller, the lower succubous; underleaves none. Fruit terminal. Involucral leaves few. Perianth cylindrical, scarcely or not at all compressed, pluriplicate, denticulate. (Name from διπλός, double, and φύλλον, leaf, on account of the folded 2-lobed leaves.)

1. D. álbicans, Dumort., var. taxifòlium, Nees. Stems ascending, almost rootless; leaves closely folded, subdenticulate, with a rudimentary pellucid line near the base or none, the lobes obtuse or acutish, the lower oblong-scymitar-shaped, the upper smaller, subovate; perianth ovate, plicate. (Jungermannia albicans and J. obtusifolia of Sulliv.; not of L. and Hook.)—Under rocks in mountain ravines and on the ground. (Eu.)—The typical form occurs in N. Scotia, distinguished by a broad pellucid median line in both lobes.

17. GEÓCALYX, Nees. ([Pl. 23.])

Leaves succubous, bidentate; underleaves 2-cleft, with linear divisions. Fruit lateral, pendent. Involucre simple, fleshy, saccate, oblong, truncate, attached to the stem by one side of the mouth. Calyptra membranous, partly adnate to the involucre. Capsule oblong. Elaters free. Antheridia in the axils of small leaves on spike-like lateral branches. (Name from γέα, the earth, and κάλυξ, a cup, from the subterranean involucres.)

1. G. gravèolens, Nees. Leaves ovate-quadrate, 2-toothed, light green; underleaves oval-lanceolate, cleft to the middle.—On the ground, and rotten logs; not rare. (Eu.)

18. LOPHOCÓLEA, Dumort. ([Pl. 23.])

Leaves succubous, dorsally decurrent, obliquely ovate-oblong, broadly truncate or bidentate; underleaves smaller, more or less quadrate, bifid or with 4–8 capillary lobes. Diœcious or monœcious. Fruit terminal on the main stem or primary branches. Involucral leaves 2–4, large, often spinulose; perianth triangular-prismatic, 3-lobed, ciliate or laciniate. Calyptra short, obovate, at length lacerate above. Capsule oblong-globose. Antheridia mostly solitary in or near the base of ordinary leaves. (Name from λόφος, a crest, and κολεός, a sheath, from the crested perianth.)

[*] Underleaves mostly bifid (or 3–4-cleft in n. 1); divisions mostly entire.

1. L. bidentàta, Dumort. Stems 1–2´ long, procumbent, sparsely branching; leaves pale green, ovate-triangular, acutely 2-toothed, the teeth oblique with a lunulate sinus; monœcious; perianth oblong-triangular, lacinate; antheridia 2–3 in a cluster, axillary.—On rocks in shady rills; not common. (Eu.)

2. L. Austìni, Lindb. Creeping; leaves uniformly deeply lobed, the lobes and usually the sinus acute; underleaves comparatively small, the lobes subulate; cells small; monœcious; antheridia solitary in the upper axils. (L. minor, Aust.; not Nees.)—On roots of trees in woods (Austin). Imperfectly known.

3. L. Macoùnii, Aust. Stems very short, prostrate, ascending at the apex, densely radiculose; leaves suberect, ovate-subquadrate, 2-lobed with obtuse lobes and sinus, or retuse or often entire; underleaves light pink, deeply bifid, the setaceous lobes spreading-incurved; monœcious; involucral leaves somewhat oblong, repandly 2–4-toothed at the apex; perianth subobovate, slightly angled.—On logs, Little Falls, N. Y. (Austin); Ont. (Macoun).

4. L. mìnor, Nees. Diffusely branching; leaves pale green, oval-subquadrate, expanded, convex, slightly rigid, equally and acutely bifid with a lunate sinus; underleaves {1/3} as large, deeply bifid, the lanceolate lobes acuminate; diœcious; involucral leaves like the cauline; perianth obtusely triangular-plicate at the apex. (L. crocata, Aust.; not Nees.)—On the ground and dry rocks in limestone regions (Austin). (Eu.)

[*][*] Divisions of the underleaves more or less dentate.

5. L. heterophýlla, Nees. ([Pl. 23.]) Stems short, creeping or ascending, much branched; leaves ovate-subquadrate, entire, retuse and bidentate on the same stem; underleaves large, 2–3-cleft; involucral leaves lobed and dentate; perianth terminal, the mouth crested.—On the ground and rotten logs in woods and swamps; very common. (Eu.)

6. L. Hàllii, Aust. Creeping, very slightly rooting; leaves subvertical, oblong, cleft nearly to the middle with obtuse sinus and erect mostly obtuse lobes; lower underleaves small, subequally 2-parted with an obtuse sinus, the upper ones larger, with a single tooth on each side or palmately 3–4-parted, the apical sublanceolate and narrowly bifid.—On the ground, Ill. (Hall).

19. CHILOSCỲPHUS, Corda. ([Pl. 23.])

Leaves succubous, dorsally decurrent, mostly rounded and entire; underleaves rooting at the base, usually deeply 2-cleft. Fruit terminal on a very short lateral branch. Involucral leaves 2–6, the outer smaller, the inner variously cut; perianth small, obconic or campanulate, 3-angled and 3-lobed only at the apex, the lobes usually spinose. Calyptra fleshy, subglobose or clavate. Capsule oblong-globose. Antheridia in the saccate bases of stem-leaves. (Name from χεῖλος, a lip, and σκύφος, a bowl, from the form of the perianth.)

[*] Underleaves 4-parted.

1. C. ascéndens, Hook. & Wils. ([Pl. 23.]) Prostrate; leaves large, pale green, ascending, roundish-oblong, slightly emarginate; involucral leaves two, 2-cleft; perianth 2–3-lobed, the lobes long and irregularly lacerate-toothed.—On rotten logs; rather common.

[*][*] Underleaves bifid.

2. C. palléscens, Dumort. Procumbent, creeping; leaves flattened, ovate-subquadrate, obtuse or retuse; underleaves ovate, distant, free; involucral leaves two, 2-toothed; perianth deeply trifid, the lobes spinose-dentate, mostly shorter than the conspicuous calyptra.—Mountains of N. Eng. (Oakes).

3. C. polyánthos, Corda. Procumbent, creeping; leaves subascending, ovate-subquadrate, truncate or subretuse; underleaves ovate-oblong, distant, free; involucral leaves 2, slightly 2-toothed; perianth 3-lobed, the short lobes nearly entire, shorter than the calyptra.—Var. rivulàris, Nees. Larger, more branching, succulent; leaves mostly rounded above; underleaves often divided in halves or wanting.—On the ground among mosses or on rotten logs, common; the variety in shaded rills or still ponds. (Eu.)

20. PLAGIOCHÌLA, Dumort. ([Pl. 24.])

Leaves large, succubous, rounded or truncate above, dentate or spinose or rarely entire, the dorsal margin reflexed; underleaves usually none. Diœcious or monœcious. Fruit terminal, or axillary by the growth of offshoots. Involucral leaves larger than the cauline; perianth laterally compressed, erect or decurved, obliquely truncate and bilabiate, the lobes entire or ciliate-dentate. Capsule thick, oval. Elaters attached to the middle of the valves. Antheridia oval, 2–3 in the axils of spicate leaves. (Name from πλάγιος, oblique, and χεῖλος, lip, from the form of the perianth.)

[*] Underleaves 2–3-cleft, fugacious.

1. P. porelloìdes, Lindenb. Branches ascending; leaves subimbricate, convex-gibbous, round-obovate, the uppermost repand-denticulate, the rest entire, the dorsal margin reflexed; perianth terminal, oblong-ovate, the mouth compressed, denticulate.—Among mosses in swamps and river-bottoms; common.

2. P. interrúpta, Dumort. ([Pl. 24.]) Prostrate, horizontally branched, copiously rooting; leaves imbricate, horizontal, oval, entire or slightly repand; underleaves lanceolate; perianth terminal, broadly obconic, the mouth compressed, repand-crenulate. (P. macrostoma, Sulliv.)—Moist banks and decayed logs, N. Eng., Ohio, and northward. (Eu.)

[*][*] Underleaves wanting.

3. P. spinulòsa, Dumort. Creeping, branches ascending; leaves remote, obliquely spreading, obovate-cuneate, the dorsal margin reflexed, entire, the ventral and apex spinulose-toothed; perianth rounded, at length oblong, the mouth spinulose.—Shaded rocks in mountain regions; rare. (Eu.)

4. P. asplenoìdes, Dumort. Branched, creeping or ascending; leaves subimbricate, obliquely spreading, round-obovate, entire or denticulate, the dorsal margin reflexed; perianth much exceeding the involucral leaves, oblong, dilated at the truncate or ciliate apex.—In rocky rivulets; common. (Eu.)

21. MÝLIA, S. F. Gray. ([Pl. 25.])

Leaves succubous, semi-vertical, circular, or ovate and pointed; underleaves subulate. Diœcious. Fruit terminal or pseudaxillary. Involucral leaves 2, clasping; perianth ovate-oblong, laterally compressed above a subterete base, the apex at length bilabiate, denticulate. Capsule ovate, coriaceous. Elaters free. Antheridia 2 in the axils of bracts clustered near the apex of distinct branches. (Name from Mylius, an early botanist.)

1. M. Taylòri, S. F. Gray. Stems erect, nearly simple, radiculose; leaves large, convex, orbicular, entire, purplish; cells large; underleaves lance-subulate, entire or subdentate; perianth terminal, oval; calyptra finally long-exserted. (Jungermannia Taylori, Hook.)—Wet rocks, high mountains of N. Eng. and N. Y. (Eu.)

22. HARPÁNTHUS, Nees. ([Pl. 23.])

Leaves succubous, semi-vertical, ovate, emarginate; underleaves connate with the leaves, ovate or lanceolate, 1-toothed at base. Diœcious. Fruit on short shoots from the axils of the underleaves, finally sublateral. Involucral leaves 2 or 4. Perianth terete, the lower half thickened. Calyptra fleshy, confluent with the perianth for {2/3} its length. Capsule oval. Antheridia 1 or 2 in the axils of bracts terminal on slender branches. (Name from ἅρπη a sickle, and ἄνθος, flower.)

1. H. scutàtus, Spruce. Stems filiform, decumbent, usually simple; leaves smaller at the base and apex of the stems, roundish-ovate, concave, sharply bidentate, the apex lunate or acute; underleaves large, acuminate, involucral leaves two, 2–3-cleft, the upper adnate to the perianth; perianth ovate, becoming obovate, obscurely 3–4-plicate, splitting above on one side; capsule deep brown. (Jungermannia scutata, Weber.)—On rotten logs in damp places; common. (Eu.)

H. Flotoviànus, Nees. ([Pl. 23.]) Stems flexuous, procumbent, mostly unbranched; leaves ovate-orbicular, horizontal, the apex contracted and emarginate with a shallow sinus; underleaves large, ovate or lanceolate, obliquely inserted, entire or more often toothed on one or both sides near the middle; diœcious; perianth subcylindric, slightly sickle-shaped, the mouth pointed at first, notched on one side and finally crenulate; antheridia elliptic, single in the base of swollen leaves. (Pleuranthe olivacea, Tayl.)—"North America" (Drummond), but not collected recently; certainly extralimital.

23. LIOCHLÆ̀NA, Nees. ([Pl. 25.])

Leaves succubous, ovate-oblong, entire or slightly retuse; underleaves none. Diœcious or monœcious. Involucral leaves 2 or 4, like the cauline; perianth pyriform, becoming cylindric, incurved, abruptly rounded at the summit, the minute orifice prominently ciliolate. Capsule oblong, long-exserted. Elaters attached to the middle of the valves. Spores minute, globose. Antheridia in the axils of ordinary leaves. Archegonia 5–12. (Name from ληῖος, smooth, and χλαῖνα, a cloak, referring to the perianth.)

1. L. lanceolàta, Nees. Closely creeping, branched; leaves sometimes decurrent; involucral leaves vertical; perianth at right angles with the stem; monœcious.—On banks and rotten logs; not rare. (Eu.)

24. JUNGERMÁNNIA, Micheli. ([Pl. 25.])

Leaves succubous, rarely subtransverse, entire, lobed or dentate, the margins never recurved; underleaves present or none. Diœcious or monœcious. Fruit terminal. Involucral leaves 4 or fewer, like the cauline or more incised, free; perianth laterally compressed or terete, usually 3–10-carinate, the usually small mouth entire or toothed. Calyptra oval-pyriform. Capsule globose or oblong, rarely cylindric. Spores minute, smooth or roughish. Archegonia 8–70. (Named for L. Jungermann, a German botanist of the 17th century.)

§ 1. JUNGERMANNIA proper. Leaves orbicular or ovate, entire or barely retuse; underleaves none (very small in n. 1).

1. J. Schràderi, Martius. ([Pl. 25.]) Creeping, flexuous; leaves round-elliptic, entire, ascending; underleaves broadly subulate, not apparent on old stems; involucral leaves large, elongated, the inner smaller and more or less laciniate; perianth oval-obovate, ascending.—On the ground and rotten logs; common. (Eu.)

2. J. sphærocárpa, Hook. Stems creeping, the tips ascending, subsimple, greenish; leaves semi-vertical, rather rigid, orbicular, obliquely spreading, decurrent dorsally, pale green; involucral leaves separate; perianth exserted, obovate-oblong, the mouth 4-cleft; capsule globose.—Mountains of N. Eng. (Austin); rare. (Eu.)

3. J. pùmila, With. Stems creeping, the tips somewhat ascending, subsimple, rooting, pale; leaves ascending, ovate, obtuse, concave, entire; involucral leaves like the cauline, erect; perianth terminal, fusiform, plicate above and denticulate; capsule oval.—On shaded rocks along rivulets, Closter, N. J. (Austin). (Eu.)

§ 2. LOPHÒZIA. Leaves roundish or subquadrate, bidentate, bifid, or sometimes 3–5-cleft; underleaves none, or small and mostly 2-parted; perianth usually strongly plicate.

[*] Underleaves present.

[+] Leaves bifid or 2-lobed.

4. J. Gillmàni, Aust. Stems short, densely cespitose, prostrate, strongly radiculose; leaves vertical, round-ovate, subconcave, bifid, the lower leaves with usually acute sinus and lobes, the upper much larger with rounded lobes and obtuse sinus; underleaves entire or the broader bifid; perianth without involucral leaves, dorsal, sessile, obovate, subgibbous, ciliate, at length much incised.—In a sandstone cave, Traine Island, L. Superior (Gillman).

5. J. Wattiàna, Aust. Stems rather thick, 2–4´´ long, fragile, subflexuose, strongly radiculose; leaves subvertical or spreading, subovate, concave, emarginately 2-lobed, the lobes acute or the upper obtuse; underleaves somewhat obsolete, hair-like or subulate, incurved; involucral leaves little larger, less deeply lobed; perianth terminal, small, ovate-gourd-shaped, whitish, ciliate.—On the ground, northern shore of L. Superior (Macoun).

[+][+] Leaves 3–5-cleft.

6. J. barbàta, Schreb. ([Pl. 25.]) Procumbent, sparingly branched; leaves roundish-quadrate, with obtuse, acute, or mucronulate lobes and obtuse undulate sinuses; underleaves broad, entire or 2-toothed, sometimes obsolete; perianth ovate, plicate-angled toward the apex, denticulate.—On rocks in mountain regions; common. (Eu.)

Var. attenuàta, Martius. Ascending, with numerous offshoots; stem-leaves semi-vertical, obliquely spreading, roundish, acutely 2–4-toothed, those of the shoots closely imbricate, premorsely 2–4-denticulate; involucral leaves two, 3-toothed; perianth oblong.—In similar localities. (Eu.)

7. J. setifórmis, Ehrh. Erect or ascending, dichotomous; leaves toothed at base, 3–4-cleft, the lobes ovate-oblong, acute, channelled; underleaves ciliate-dentate at base, deeply bifid, the divisions lanceolate, acuminate; involucral leaves more toothed than the cauline; perianth terminal, oval, plicate.—Alpine summits of N. H. (Oakes). (Eu.)

[*][*] Underleaves wanting.

[+] Leaves 2-toothed; involucral leaves 2–4-cleft.

8. J. alpéstris, Schleich. Stems creeping, crowded, bifid-branching, the ends ascending; leaves semi-vertical, ovate subquadrate, obliquely toothed, the teeth unequal, acute or mucronulate, distant; involucral leaves wider, 2–3-cleft; perianth twice as long, oblong, smooth, the mouth complicate; capsule oval.—Alpine region of N. H. (Oakes). (Eu.)

9. J. ventricòsa, Dicks. Stems dense, close-creeping, branching from beneath; leaves semi-vertical, subquadrate, mostly flat, broadly and acutely emarginate-bidentate, often bearing globules; involucral leaves larger, round, erect-spreading, 3–4-cleft, subdentate; perianth ovate, inflated, narrowly complicate above; capsule oval.—On the ground and rotten wood in the mountains, and far northward; common. (Eu.)

10. J. Wallrothiàna, Nees. Minute, blackish; stems creeping, strongly rooting, subsimple; leaves clasping, semi-vertical, closely imbricate, ovate-quadrate, concave, obtusely bidentate with an obtuse sinus, or acute in the upper leaves; involucral leaves larger, erect, connate at base, 3-toothed, wavy-plicate; perianth oval-cylindric, plicate and subdentate, pellucid, reddish below.—On coarse sand in the White Mts. (Oakes). (Eu.)

[+][+] Leaves bifid or 2-lobed, the ventral lobe often inflexed or subcomplicate; involucral leaves merely toothed, except in n. 11.

11. J. láxa, Lindb. Widely creeping, mostly simple, usually purplish-black; leaves imbricate, or distant on the erect fertile stems, 2–3-lobed, the lobes obtuse, wavy; cells very large, lax; involucral leaves 2, wide, short, cristate-undulate, obtusely many-lobed; perianth exserted, long-clavate, sub-plicate above, minutely ciliate. (J. polita, Aust.; not Nees.)—Among Sphagnum near Closter, N. J. (Austin).

12. J. excìsa, Dicks. Stems closely creeping, short, subsimple, rather rigid; leaves semi-vertical, erect-spreading, pellucid, roundish, with straight acute lobes and deep obtuse sinus; involucral leaves erect, quadrate, usually 4–5-toothed; perianth erect, oblong, pale, banded and spotted with pink, plicate above, irregularly denticulate.—Sterile grounds in open woods; common. (Eu.)

Var. críspa, Hook. Leaves round-quadrate, closely imbricate, deeply and obtusely 2–3-cleft; involucral leaves 3–4-cleft, connate at base, subserrate. (J. intermedia, Lindenb.)—In crevices of rocks, N. Y. and N. J. (Austin). (Eu.)

13. J. incìsa, Schrad. Stems thick, rooting, closely creeping or ascending; leaves crowded, semi-vertical, complicate, subquadrate, 2–6-cleft, the acute lobes unequal, more or less spinulose-dentate; involucral leaves similar, more plicate and dentate, free; perianth short, oval or obovate, plicate above, denticulate.—On rotten wood in the mountains, and northward. (Eu.)

§ 3. SPHENÓLOBUS. Leaves 2-lobed, subtransverse, complicate-concave; underleaves none; involucral leaves 2–3-cleft. (Verging toward Marsupella on one side and Diplophyllum on the other.)

14. J. Michaùxii, Weber. Stems ascending, flexuous by repeated innovations below the summit; leaves crowded, subvertical, erect-spreading, subsaccate at base, subquadrate, bifid with straight acute lobes and a narrow sinus; involucral leaves similar, the outer serrulate, the inner smaller; perianth ovate-subclavate, obtuse, plicate above, fringed.—Fallen trunks, mountains of N. Y. and N. Eng.; common. (Eu.)

15. J. minùta, Crantz. Rootless; leaves cleft ¼–½ their length, the lobes ovate, subequal, acute or obtuse, entire, or gemmiparous ones subdentate; involucral leaves trifid; perianth oval-oblong or subcylindric.—On rocks in high mountain regions, and northward. (Eu.)

16. J. Helleriàna, Nees. ([Pl. 25.]) Creeping, entangled; leaves spreading, subascending, cleft {1/3}–½ their length, the lobes equal, acute, entire or serrate; involucral leaves 2–3-cleft, spinulose serrate; perianth ovate, the mouth contracted.—On rotten wood, N. Y., N. Eng., and northward. (Eu.)

§ 4. GYMNOCÓLEA. Leaves 2-lobed; underleaves none; involucral leaves like the cauline; perianth pedunculate, denticulate.

17. J. inflàta, Huds. ([Pl. 25.]) Procumbent or ascending, loosely radiculose, branching; leaves semi-vertical, roundish-elliptic, inequilateral, the sinus and unequal lobes obtuse; perianth terminal or at length dorsal, oval or pyriform, smooth, the mouth connivent; capsule oblong.—On sterile ground and rocks, N. J. (Austin), and northward in the mountains. (Eu.)

25. MARSUPÉLLA, Dumort. ([Pl. 23.])

Stems dorsally compressed, with rootlets at the base and often producing somewhat leafless runners. Leaves transverse, complicate-bilobed; involucral leaves 2 or 4, connate with the perianth. Perianth tubular or oval, subcompressed parallel to the base of the leaves. Elaters free. Spores round, rufous (in our species). Antheridia mostly terminal. (Name a diminutive of marsupium, a pouch, from the form of the perianth.)

1. M. sphacelàta, Dumort. Stems erect, subflexuous, pale brown; leaves rather distant, concave, obovate to obcordate, somewhat clasping, the sinus narrow; diœcious; involucral leaves larger than the cauline, cordate; perianth free at the apex, with 4–5 broad acute teeth; antheridia 1–3, in short terminal spikes.—Wet rocks, mountains of N. Eng. to N. J., and southward. (Eu.)

2. M. emarginàta, Dumort. ([Pl. 23.]) Stems simple or innovating at the summit, rigid, somewhat thickened upward; leaves usually broader than long, round-cordate or subquadrate, lobes obtuse or mucronate, sinus acute; diœcious; involucral leaves 4–8, usually larger, more deeply and acutely emarginate; perianth urceolate, the closed apex splitting into 4–5 triangular lobes; antheridia 2–3, oval, axillary in terminal spikes. (Sarcoscyphus Ehrharti, Corda.)—On wet rocks, chiefly in mountain rivulets, N. Y. and N. Eng. Floating forms are longer with distant leaves. (Eu.)

3. M. adústa, Spruce. Stems minute, clavate; leaves (5–8 pairs) imbricate, round or broadly ovate from a sheathing base, acutely lobed with angular sinus; monœcious; perianth included, campanulate, crenate becoming irregularly lobed; spores punctate; antheridia 1 or 2, oval, in the axils of the lower involucral leaves. (Gymnomitrium adustum, Nees.)—Alpine region of the White Mts. (Oakes, Austin). (Eu.)

26. NÁRDIA, S. F. Gray. ([Pl. 25])

Stems laterally compressed, usually without runners. Leaves succubous, subconcave or flat, the apex rounded, rarely retuse or bidentate; underleaves none (in our species). Monœcious or diœcious. Involucral leaves 2–4 pairs, connate at base. Perianth subcompressed laterally, connate with the involucral leaves. Antheridia terminal on somewhat spike-like stems. (Named for S. Nardi, an Italian abbot.)

§ 1. EÙCALYX. Perianth connate at base with the inner involucral leaves, somewhat surpassing them, 3–8-carinate, the mouth constricted.

1. N. hyalìna, Carring. Creeping, with ascending tips, the branches dichotomous-fastigiate, with claret-colored rootlets; leaves loosely imbricate, decurrent, roundish, repand-undulate; monœcious or diœcious; involucral leaves broader, appressed, one connate with the lower third of the perianth, which is somewhat exserted, obovate, plicate with acute rough angles, rostellate, at length 4-cleft; capsule round-ovate. (Jungermannia hyalina, Lyell.)—On banks in woods, Closter, N. J. (Austin), Ohio (Lesquereux). (Eu.)

2. N. crenulàta, Lindb. ([Pl. 25.]) Prostrate, branching; leaves orbicular, entire, larger toward the involucre and with large marginal cells; diœcious; involucral leaves 2, rarely 3, adnate to the base of the perianth, which is flattened or terete, more or less regularly 4–5-plicate, the angles smooth; mouth much contracted, toothed. (Jungermannia crenulata, Smith.)—On the ground in old fields, N. Y. and southward. (Eu.)

3. N. crenulifórmis, Lindb. Densely cespitose; fertile stems creeping, thickened upward, with numerous purple rootlets, the sterile subascending, attenuate upward; leaves subdecurrent, obliquely spreading, orbicular, concave, entire or nearly so; perianth small, subobovate, more or less connate with the involucral leaves, not exserted or slightly so, rooting at base, triquetrous above, becoming 4–7-plicate; calyptra often violet-purple; capsule oval-globose. (Jungermannia crenuliformis, Aust.)—On rocks in rivulets, Closter, N. J. (Austin), Coshocton Co., Ohio (Sullivant).

4. N. bifórmis, Lindb. Densely cespitose, much branched, innovating from beneath; rootlets numerous; leaves scarcely imbricate, alternate, spreading, obliquely semicircular or broadly ovate, retuse or entire, decurrent dorsally; cells large, hyaline; branch-leaves half as large, ovate or obovate, scarcely decurrent; diœcious; antheridia solitary; fruit unknown. (Jungermannia biformis, Aust.)—On steep wet rocks, Delaware Water Gap, N. J. (Austin).

§ 2. CHASCÓSTOMA. Perianth exserted, subcampanulate and open, deeply laciniate, connate with the involucral leaves.

5. N. fossombronioìdes, Lindb. Stems densely cespitose, ascending; rootlets numerous, purple; leaves 2-ranked, subvertical, spreading-subrecurved, rooting, closely imbricate, orbicular, clasping by a slightly cordate base, subventricose, undulate-repand, the apex uniplicate and slightly emarginate; monœcious; perianth very large, 6–10-plicate, the lobes entire; calyptra violet; capsule short-oval. (Jungermannia fossombronioides, Aust.)—On rocks in a rivulet, Closter, N. J. (Austin), and southward.

27. GYMNOMÍTRIUM, Corda. ([Pl. 23.])

Leaves closely imbricated, 2-ranked on fascicled ascending julaceous stems, emarginate-bidentate; underleaves none. Diœcious. Involucre double, the inner shorter, of 2 or more dentate and deeply cleft leaves. Calyptra short, campanulate. Capsule globose, the valves at length reflexed. Elaters caducous. Antheridia in the axils of leaves, oval, stipitate. (Name from γυμνός, naked, and μιτρίον, a little cap.)

1. G. concinnàtum, Corda. Stems simple or imbricately branching, thickened at the apex; leaves ovate, bifid, with a narrow scarious margin. (Cesia concinnata, S. F. Gray.)—Alpine regions of the White Mts. (Oakes).—Grayish or silvery-olive. (Eu.)

28. FOSSOMBRÒNIA, Raddi. ([Pl. 23.])

Stems thalloid, with large subquadrate succubous leaves; underleaves none. Diœcious or monœcious. Fruit terminal or by innovation dorsal on the main stem. Involucral leaves 5–6 (in our species), small, subulate, adnate. Perianth open-campanulate or obpyramidal, crenate-lobed. Calyptra free, sub-globose. Capsule short-pedicelled, globose, irregularly valved. Elaters very short, 1–3- (mostly 2-) spiral, free. Spores large, very rough. Antheridia 2–3, short-pedicelled, naked. Perfect archegonia 2–3. (Named for V. Fossombroni, an Italian Minister of State.)

[*] Plant large or of medium size; stems mostly simple.

1. F. pusílla, Dumort. ([Pl. 23.]) Stems 6–10´´ long; leaves retuse, entire or irregularly indented; perianth obconic, dentate; elaters short and thick; spores brown, depressed-globose-tetrahedral, 40 µ broad, crested, the slender crests pellucid, rarely becoming confluent.—On damp ground. Its occurrence in America is doubtful. (Eu.)

2. F. Dumortièri, Lindb. Cespitose, greenish or brownish-yellow; stems 3–6´´ long, 1´´ wide, shortly bifurcate; rootlets copious, purple; leaves numerous, smaller toward each end of the stem; monœcious; perianth large, broadly obpyramidal; calyptra nearly as long; elaters scanty; spores globose-tetrahedral yellowish-brown, regularly pitted.—White Mts. (Farlow), N. J. (Austin), and perhaps elsewhere; confused with n. 1.

3. F. angulòsa, Raddi. Stems narrowly forked at the apex; leaves horizontal, subquadrate, the upper undulate-lobed; diœcious; perianth dilated-conic, crenate; spores brownish-yellow, globose-tetrahedral, not depressed, 30 µ broad, deeply reticulated, the reticulations large, 5–6-angled.—Brackish meadows, common; fruiting in early spring. (Eu.)

[*][*] Plant minute; stems forked or fastigiately divided.

4. F. crístula, Aust. Stems 1–2´´ long; leaves whitish, quadrate or round-obovate, subentire, strongly crisped-undulate; capsule immersed on a short pedicel; elaters short, more or less diverse, with a single narrow annular and spiral fibre; spores pale fuscous, more or less tuberculate.—On moist sand in unfrequented paths, Batsto, N. J. (Austin).

29. PALLAVICÍNIA, S. F. Gray. ([Pl. 22.])

Thallus with a distinct costa. Fruit arising from the costa, at first terminal, becoming dorsal. Diœcious. Involucre cup-shaped, short-lacerate. Perianth long-tubular, denticulate. Calyptra irregularly lacerate. Capsule slender-cylindric. Elaters slender, free. Spores minute. Antheridia dorsal, covered with minute fimbriate scales. (Named for L. Pallavicini, Archbishop of Genoa.)

1. P. Lyéllii, S. F. Gray. Thallus thin, 1–4´ long, 3–5´´ wide, simple or bifid, the margin entire, slightly crenate or serrate; cells large, oblong-hexagonal; perianth erect, fleshy (5 cells thick below), the somewhat constricted mouth lobate-ciliolate; pedicel long, exceeding the thallus; capsule cylindric, five times as long as broad. (Steetzia Lyellii, Lehm.)—Among mosses in swamps and on dripping rocks; common, especially southward. (Eu.)

30. BLÀSIA, Micheli. ([Pl. 23.])

Thallus simple or forked or stellate, with sinuous margins. Diœcious. Fruit from an oval cavity in the costa. Involucre mostly none. Calyptra obovate. Capsule oval-globose. Antheridia immersed in the thallus, covered with dentate scales. Gemmæ globose, issuing by a slender ascending tube from large flask-shaped receptacles which are immersed in the thallus. (Named for Blasius Biagi, a monk of Valombrosa and companion of Micheli.)

1. B. pusílla, L. Thallus ¾–1½´ long, 2–3´´ wide, narrowly obovate, the margins pinnatifid-sinuous.—Wet banks; common. (Eu.)

31. PÉLLIA, Raddi. ([Pl. 23.])

Thallus with a broad indeterminate costa. Monœcious or diœcious. Fructification dorsal near the end of the thallus. Involucre short, cup-shaped, lacerate-dentate. Calyptra membranous, oval, longer or shorter than the involucre. Capsule globose. Elaters long, free. Antheridia globose, immersed in the costa. (Named for A. L. Pelli, an Italian botanist.)

[*] Monœcious.

1. P. epiphýlla, Raddi. ([Pl. 23.]) Thallus oblong, lobed and sinuate, somewhat fleshy, much thickened in the middle; capsule exserted.—On the ground in wet places; not uncommon eastward. (Eu.)

[*][*] Diœcious.

2. P. endiviæfòlia, Dumort. Thallus flat, green or purplish, broadly linear, dichotomous, the margin mostly undulate or crisped.—On the ground and in ditches; common, but often confused with n. 1. (Eu.)

3. P. calycìna, Nees. Thallus dichotomous, proliferous, the early divisions linear-oblong, the margins ascending and remotely sinuate, the later divisions linear-palmatifid, coarsely nerved; cells large, hexagonal; involucre ciliate-fringed or lacerate; calyptra smooth, included.—Wet limestones and shales. (Eu.)

32. METZGÈRIA, Raddi. ([Pl. 23.])

Thallus linear, dichotomous, with well defined costa. Diœcious. Fructification arising from the under side of the costa. Involucre 1-leaved, scale-like, at length ventricose. Calyptra clavate or pyriform, fleshy. Capsule short-pedicelled. Elaters unispiral, some remaining attached to the tips of the valves. Spores minute, mostly smooth. Antheridia globose, enclosed in a scale on the under surface of the costa. (Named for J. Metzger, a German botanist.)

[*] Densely villous throughout.

1. M. pubéscens, Raddi. Thallus 1–2´ long, 1´´ wide, alternately pinnate or somewhat decompound, the short linear branches of uniform width, flat, the margin undulate; hairs longer beneath, single or in twos and threes near the margin, irregularly curved; midrib nearly without cortical layer, with 6–10 (mostly 8) rows of very uniform peripheral cells; diœcious.—In mountain regions, eastward. (Eu.)

[*][*] Hairy on the margins and midrib beneath, smooth above; diœcious (n. 4 monœcious).

2. M. myriópoda, Lindb. Thallus elongated (2´ long, ½´´ wide), dichotomous, the long linear branches of uniform width, convex above, the reflexed margins not undulate; midrib densely pilose beneath; hairs rather long, straight or nodding, the marginal mostly in clusters of 3–6, some with discoid tips; midrib covered above with 2 rows of enlarged cells, and beneath with 3–7 (usually 4–6) rows of smaller cells, lax and often indistinct. (M. furcata, Sulliv., in part; not Nees.)—Shaded rocks and trees in the Alleghanies (Sullivant), and southward.

3. M. hamàta, Lindb. Like the last; thallus much elongated (4´ long, 1–1½´´ wide); hairs very long, divaricate and hooked-deflexed, the marginal in twos, rarely with discoid tips; midrib covered above and below with two rows of enlarged lax cells. (M. furcata, Sulliv., in part.)—Alleghany Mts. (Sullivant).

4. M. conjugàta, Lindb. Thallus 1½´ long, ½–1´´ wide, usually dichotomous, the short branches irregular in width, convex above, the margins more or less undulate; hairs rather long, straight, divaricate, the marginal usually in twos, very often disk-bearing; midribs covered above with 2, below with 3–6 rows of enlarged lax cells.—On shaded rocks and trunks of trees, central N. Y., and southward. (Eu.)

33. ANEÙRA, Dumort. ([Pl. 23.])

Thallus fleshy, prostrate or assurgent from a creeping base; costa obscure. Diœcious or monœcious. Fructification arising from the under side near the margin. Involucre cup-shaped, short and lacerate, or none. Calyptra large, fleshy, more or less clavate. Capsule large, oblong-cylindric. Elaters unispiral, in part adherent to the tips of the valves. Spores minute, smooth or minutely roughened. Antheridia immersed in the surface of receptacles proceeding from the margin of the thallus. (Name from α- privative, and νεῦρον, a nerve.)

[*] Thallus narrow (about 1´´ wide), palmately divided.

1. A. látifrons, Lindb. Thallus cespitose, ascending or erect, usually dark green, 6–9´´ long, mostly pellucid; branches linear, obtuse and emarginate, plano-convex; cells large, oblong-rhombic; monœcious; archegonia 3–10, short, conic; calyptra white, verrucose, pyriform-clavate; capsule oval, brown; spores 12½–14½ µ broad, globose, minutely and densely papillose; antheridia globose. (A. palmata of authors; not Dumort.)—On rotten logs; common.

[*][*] Thallus narrow (about 1´´ wide), pinnate or bipinnate.

2. A. multífida, Dumort. Thallus prostrate, brownish-green, pinnately divided, the primary portion biconvex, somewhat rigid, the branches horizontal, pectinately pinnate with narrow linear divisions; monœcious; fructification rising from the primary part or from the branches; involucre fleshy; calyptra tuberculate.—Var. màjor, Nees. Primary portion and branches thick, the branches interruptedly pinnate with short obtuse divisions.—On decayed wood and moss in swamps, N. J. (Austin), and south in the mountains. (Eu.)

3. A. pinnatífida, Nees. Thallus pinnately divided or subsimple, flat or somewhat channelled; branches horizontal, the broader pinnatifid or dentate, obtuse; calyptra somewhat smooth.—On dripping rocks, Hokokus, N. J. (Austin), N. Haven, Conn. (Eaton). (Eu.)

[*][*][*] Thallus wider (2´´ or more), simple or irregularly lobed.

4. A. séssilis, Spreng. Thallus decumbent, irregularly lobed, 1–2´ long, 3–5´´ wide; involucre none; pedicel ¾–1´ long, sometimes folded upon itself and remaining within the calyptra, the capsule thus appearing sessile; antheridia on elongated receptacles.—Wooded swamps. Elongated floating forms, 5–6´ long, have been found in the White Mts. (Farlow, Faxon).

5. A. pínguis, Dumort. Thallus 1–2´ long, decumbent or ascending, fleshy, linear-oblong, simple or slightly lobed, the margin sinuate; diœcious; involucre short, lacerate; calyptra cylindric, smooth; capsule brownish, furrowed; antheridia in 2-lobed receptacles.—Wet banks, N. J. to Ohio, and southward. (Eu.)

Order 138. ANTHOCEROTÀCEÆ. (Horned Liverworts.)

Plant-body a thallus, irregularly branching, flaccid, without epidermis or pores, and more or less vesiculose. Involucre single, tubular. Calyptra rupturing early near the base, and borne on the apex of the capsule. Capsule dorsal, pod-like, erect or curved outward, more or less perfectly 2-valved, usually stomatose, tapering into a pedicel or often sessile with a bulbous base. Columella filiform. Elaters with or without spiral fibres. Spores flattish, more or less convex-prismatic, papillose or smooth.

1. Anthoceros. Capsule narrowly linear, exsertly pedicelled, 2-valved. Elaters present.

2. Notothylas. Capsule very short, sessile, not valved below the middle. Elaters not obvious.

1. ANTHÓCEROS, Micheli. ([Pl. 22.])

Thallus dark green or blackish, usually depressed, variously lobed, with large chlorophyll-grains, frequently glandular-thickened at the apex or in lines along the middle so as to appear nerved. Monœcious or diœcious. Capsule linear, 2-valved, exsertly pedicelled. Elaters simple or branched, often geniculate, more or less heteromorphous, the fibres wanting or indistinct. (Name from ἄνθος, flower, and κέρας, horn, from the shape of the capsule.)

1. A. læ̀vis, L. ([Pl. 22.]) Thallus smooth, nearly flat above; diœcious; involucre 1–2´´ long, trumpet-shaped when dry, repand-toothed; capsule pale brown or yellowish, 1–1½´ long; elaters rather short, yellowish; spores yellow, nearly smooth, angular.—Wet clay banks, from Canada south and westward. (Eu.)

2. A. punctàtus, L. Thallus small, depressed, or often cespitose and erect, more or less glandular; monœcious; involucre rather short, oblong-linear, slightly repand, sometimes scarious at the mouth; capsule 1´ high, black; elaters fuscous, flattish, geniculate; spores black, strongly muriculate, sharply angled.—Wet banks, Canada to Mo., and southward. (Eu.)

2. NOTOTHỲLAS, Sulliv. ([Pl. 22.])

Thallus orbicular, tender, laciniate and undulate or crisped, papillose-reticulate. Monœcious. Involucre sessile, continuous with the thallus, opening irregularly above. Capsule very short, oblong-globose or ovate-cylindric, pedicelled from a thickened bulb, 2-valved to the middle or rupturing irregularly. Elaters none, or fragmentary and inconspicuous. Spores subglobose, smoothish. Antheridia elliptic-globose, immersed in the thallus. (Name from νῶτος, the back, and θυλάς, a bag, from the shape and position of the involucre.)

1. N. orbiculàris, Sulliv. ([Pl. 22.]) Thallus 3–8´´ wide; capsules 1–2´´ long, erect or decurved, wholly included or slightly exserted, of thin and loose texture, with a suture on each side; spores light yellowish-brown. (Including N. valvata, Sulliv.)—Wet places, Canada to the Gulf.

2. N. melanóspora, Sulliv. Thallus small, depressed or sometimes cespitose, of lax texture; capsule often without sutures; spores dark brown, a half larger.—Moist ground, Ohio (Sullivant).

Order 139. MARCHANTIÀCEÆ. Liverworts.

Plant-body a thallus, dichotomous or subpalmately branching, usually innovating from the apex or beneath it, more or less thickened in the middle, and bearing numerous rootlets beneath and usually colored or imbricating scales. Epidermis usually more or less distinct and strongly porose above. Capsules globose, rarely oval, opening irregularly, pendent from the under side of a peduncled disk-like receptacle (carpocephalum). Elaters present, mostly 2-spiral.

[*] Thallus plainly costate, distinctly porose except in n. 6.

[+] Gemmæ present on sterile stems.

1. Marchantia. Gemmæ in cup-shaped receptacles. Fertile receptacle 7–11-rayed.

8. Lunularia. Gemmæ in crescent-shaped receptacles. Fertile receptacle cruciform.

[+][+] Gemmæ wanting.

[++] Receptacle conic-hemispherical, 2–4-lobed; perianth lobed or fringed.

2. Preissia. Receptacle 2–4-lobed, with as many alternate rib-like rays. Perianth 4–5-lobed.

3. Fimbriaria. Receptacle 4-lobed. Perianth conspicuous, split into 8–16 fringe-like segments.

[++][++] Receptacle more or less conical; perianth none.

4. Conocephalus. Thallus very large, strongly areolate. Receptacle conical, membranous.

5. Grimaldia. Thallus small. Peduncle chaffy at base and apex. Receptacle conic-hemispheric, truncately 3–4-lobed.

6. Asterella. Thallus eporose. Receptacle conic-hemispheric, becoming flattened, acutely 4- (1–6-) lobed.

[*][*] Thallus thin, ecostate or barely costate.

7. Dumortiera. Receptacle convex, 2–8-lobed. Perianth none.

1. MARCHÁNTIA, Marchant f. ([Pl. 22.])

Thallus large, forking, areolate, porose, with broad diffused midrib; gemmæ in a cup-shaped receptacle. Diœcious. Fertile receptacle peduncled from an apical sinus of the thallus, radiately lobed. Involucres alternate with the rays, membranous, lacerate, enclosing 3–6 1-fruited cleft perianths. Calyptra persistent. Capsule globose, exserted, pendulous, dehiscing by several revolute segments. Elaters long, attenuate to each end. Spores smooth. Antheridia immersed in a peduncled disk-like radiate or lobed receptacle. (Named for Nicholas Marchant, a French botanist.)

1. M. polymórpha, L. Thallus 2–5´ long, ½–1½´ wide, numerously porose, venulose; receptacle divided into usually 9 terete rays; peduncles 1–3´ high; antheridial disk crenately or palmately 2–8-lobed, on a peduncle 1´ high or less.—Everywhere common. (Eu.)

2. PREÌSSIA, Nees. ([Pl. 22.])

Thallus obcordate, sparingly forked, increasing by joints; pores conspicuous; gemmæ none. Diœcious or monœcious. Fertile receptacle hemispheric, 1–4-lobed, with as many alternating shorter rib-like rays. Outer involucres attached beneath the lobes, 1–3-fruited, opening outward by an irregular line; perianth obconic-campanulate, angular, unequally 4–5-lobed. Calyptra persistent. Capsule large, distinctly pedicelled, dehiscing by 4–8 revolute segments. Elaters short. Spores coarsely tuberculate. (Named for L. Preiss, a German botanist.)

1. P. commutàta, Nees. Thallus 1–2´ long, with conspicuous white pores above, and dark purple scales beneath; usually monœcious; peduncle ½–1´ high; capsules conspicuous, dark purple; antheridia in a peduncled disk-like receptacle. (P. hemisphærica, Cogn.)—On slaty and limestone rocks, from N. J. north and westward. (Eu.)

3. FIMBRIÀRIA, Nees. ([Pl. 22.])

Thallus thickened in the middle by a keeled costa, usually conspicuously porose, with dark purple scales beneath; gemmæ none. Monœcious. Receptacle rising from the apex, conic or hemispheric, concave beneath and expanded into usually 4 large campanulate 1-fruited involucres. Perianth oblong-oval or subconic, exserted half its length and cleft into 8–16 fringe-like segments. Calyptra with a long style, fugacious. Capsule nearly sessile, irregularly circumscissile. Elaters rather short, 1–4-spiral. Spores angular, subreticulated. Antheridia immersed in the thallus. (Name from fimbria, a fringe, alluding to the perianth.)

1. F. tenélla, Nees. Thallus of one or more long-wedge-shaped emarginate divisions about 6–9´´ long, grayish-green and porose above, purple on the margins; peduncle 1´ high or more, usually purple; receptacle obtusely conic; perianth white, 8-cleft.—On damp ground in sandy fields or on rocks, central N. Y. to Mo., and southward.

4. CONOCÉPHALUS, Neck. ([Pl. 22.])

Thallus dichotomous, copiously reticulate and porose, with a narrow costa; gemmæ none. Receptacle conic-mitriform, membranous. Involucres 5–8, tubular, 1-fruited, suspended from the apex of the peduncle; perianth none. Calyptra persistent, campanulate, 2–4-lobed at the apex. Capsule pedicelled, oblong-pyriform, dehiscing by 5–8 revolute segments. Elaters short, thick. Spores muriculate. Antheridia imbedded in an oval disk sessile near the apex of the thallus. (Name from κῶνος, a cone, and κεφαλή, a head.)

1. C. cónicus, Dumort. Thallus 2–6´ long, ½–¾´ wide; receptacle conic, striate, crenate. (Fegatella conica, Corda.)—Shady banks; common. (Eu.)

5. GRIMÁLDIA, Raddi. ([Pl. 23.])

Thallus thick, more or less channelled, dichotomous, innovating from the apex, with thick epidermis, closely areolate and porose-scabrous above, purple and more or less scaly beneath; gemmæ none. Monœcious or diœcious. Receptacle peduncled, hemispherical or conoidal, 3–4-lobed. Involucres as many, 1-fruited, each a distention of the lobe. Capsule filling the involucre, circumscissile in the middle, the calyptra persistent at its base. Antheridia in an oval or obcordate disk immersed in the apex of the thallus. (Named for D. Grimaldi, an Italian botanist.)

1. G. bárbifrons, Bisch. ([Pl. 23.]) Thallus linear-obcuneate, 3–6´´ long, 1–2´´ wide, 2-lobed at the apex, pale green with usually distinct whitish pores, the scales beneath often extending far beyond the margin and becoming whitish; peduncle profusely chaffy at base and apex, sometimes much reduced; antheridial disks obcordate. (Including G. sessilis, Sulliv.)—Thin soil on rocks, Conn. and N. J. to Iowa; rare or local. (Eu.)

2. G. rupéstris, Lindenb. Thallus 3–6´´ long, 1–3´´ wide, with membranous margins; receptacle small, hemispherical, 1–4-fruited, the peduncle about 1´ high, sparingly scaly at base, barbulate at the apex; involucre short, crenulate; spores tuberculate. (Duvalia rupestris, Nees.)—On calcareous or shaly rocks, N. Y. and Ohio. (Eu.)

6. ASTERÉLLA, Beauv. ([Pl. 22.])

Thallus rigid, very indistinctly porose, the midrib broad, strong and distinct. Receptacle conic-hemispheric, becoming flattened, 1–6- (usually 4-) lobed. Monœcious. Involucres coherent with the lobes, 1-fruited, 2-valved. Calyptra minute, lacerate, persistent at the base of the capsule. Capsule greenish, rupturing by irregular narrow teeth or by a fragmentary operculum. Elaters moderately long, mostly 2-spiral. Spores tuberculate. Antheridia in sessile lunate disks. (Diminutive of aster, a star, from the form of the receptacle.)

1. A. hemisphæ̀rica, Beauv. Thallus forking and increasing by joints, pale green, purple beneath; receptacle papillose on the summit (less so at maturity); peduncle bearded at base and apex, ¾–1´ long, often 2–3 times longer after maturity. (Reboulia hemisphærica, Raddi.)—Shaded banks, chiefly along streams; more common southward.—A smaller form or perhaps variety (Reboulia microcephala, Nees; R. Sullivantii, Lehm.) occurs in Penn., Ohio, and southward. (Eu.)

7. DUMORTIÈRA, Nees. ([Pl. 22.])

Thallus large, thin, soft, with a slight costa, dichotomous, usually with scattered hair-like rootlets beneath; gemmæ none. Receptacle convex, 2–8-lobed. Involucres 1-fruited, connate with the lobes beneath, horizontal, opening by a vertical terminal slit. Capsule distinctly pedicelled, oblong-globose, dehiscing by 4–6 irregular valves. Elaters 2–3-spiral, parietal, very long, straight, attenuate both ways. Spores muriculate. Antheridia in a short peduncled disk paleaceous beneath. (Named for B. C. Dumortier, a Belgian botanist.)

1. D. hirsùta, Nees. Thallus 2–5´ long, 6–9´´ wide, deep green, becoming blackish, entire on the margins, naked above or with a delicate appressed pubescence; diœcious; receptacle many-fruited, the margin closely hairy; peduncle rather long, chaffy at the apex.—On moist calcareous rocks, Easton, Penn. (Porter), and southward.

8. LUNULÀRIA, Micheli. ([Pl. 25.])

Thallus oblong with rounded lobes, distinctly areolate and porose, with imbricate sublunate scales beneath; gemmæ in crescent-shaped receptacles. Diœcious. Fertile receptacle usually cruciately divided into 4 horizontal segments or involucres, which are tubular, vertically bilabiate and 1-fruited. Calyptra included, persistent. Capsule exserted, 4–8-valved. Elaters short, very slender, mostly free. Spores nearly smooth. Antheridia borne in the apical sinus of the thallus. (Name from lunula, a little moon.)

L. vulgàris, Raddi. Thallus 1–2´ long, forked, innovating from the apex, with a somewhat diffuse costa; peduncle very hairy, 1–1½´ long.—Introduced into greenhouses; always sterile, but easily recognized by the characteristic receptacles. (L. cruciata, Dumort.) (Int. from Eu.)

Order 140. RICCIÀCEÆ.

Plant-body a dichotomously branching thallus, terrestrial or aquatic. Capsules short-pedicelled, or sessile on the thallus, or immersed in its substance, free or connate with the calyptra, globose, at length rupturing irregularly. Calyptra crowned with a more or less deciduous point. Elaters none. Spores usually angular, reticulate or muriculate. Antheridia ovate, immersed in the thallus in flask-shaped cavities with protruding orifices (ostioles).

1. Riccia. Capsule immersed in the thallus. Involucre none.

2. Sphærocarpus. Capsule sessile on the thallus. Involucre inflated-pyriform.

1. RÍCCIA, Micheli. ([Pl. 22.])

Thallus at first radiately divided, the centre often soon decaying; the divisions bifid or di–tri-chotomous, flat or depressed or channelled above, usually convex and naked or squamulose beneath; margins naked or spinulose-ciliate; epidermis usually distinct, eporose; air-cavities evident or wanting. Capsule immersed, sessile. Calyptra with a persistent style. Spores alveolate or muriculate, usually flattened and angular. (Named for P. F. Ricci, an Italian nobleman, patron of Micheli.)

§ 1. LICHENÒDES. Fruit mostly protuberant above; spores about 84 µ broad, issuing through openings in the upper surface of the thallus; terrestrial species (on damp, usually trodden or cultivated ground), without air-cavities.

[*] Thallus naked, without cilia or scales.

1. R. Fróstii, Aust. Thallus orbicular, 6–12´´ broad, thinnish, grayish-green, the apex and narrowly membranous margins sometimes purplish, minutely pitted; divisions linear or subspatulate, subtruncate and slightly emarginate; rootlets smooth or obsoletely papillose within; capsules very prominent beneath; spores barely 50 µ broad, nearly round, somewhat margined, with depressed sides when dry, fuscous.—Ohio, Ill., and westward.

[*][*] Thallus with white scales beneath (dark purple in n. 4), the margin naked.

2. R. sorocárpa, Bisch. Thallus 3–8´´ in diameter, pale green becoming whitish, finely reticulate, subradiately or dichotomously divided, the oblong-linear segments subacute, deeply sulcate, with a few inconspicuous scales toward the apex not extending beyond the margin; margins erect when dry; spores issuing through chinks early appearing along the groove above.—Thin rocky soil and cultivated fields, Closter, N. J. (Austin), western N. Y. (Clinton), and Ill. (Hall). (Eu.)

3. R. lamellòsa, Raddi. Thallus pale green, elegantly reticulated, subradiately divided, the divisions obovate or obcordate, bifid or 2-lobed, 2–5´´ long, channelled at the apex, with membranous ascending margins, and furnished beneath with transverse scales which extend considerably beyond the margin; spores much as in n. 2.—Thin rocky soil, Closter, N. J. (Austin).

4. R. nigrélla, DC. Thallus dichotomously divided, the divisions linear, channelled, with entire narrowly membranous margins, green above, dark purple beneath and furnished with transverse semicircular scales not exceeding the margin.—Rocky ground, N. Y. (Torrey), and Chester, Penn. (Porter). (Eu.)

[*][*][*] Thallus more or less ciliate, naked beneath or obsoletely squamous along the extreme edge.

5. R. arvénsis, Aust. Thallus much divided, 3–9´´ broad, papillose-reticulate, dull green both sides, becoming fuscous above, the flat margins at length purple; divisions sulcate, dichotomous, the linear-elliptic or subspatulate lobes acutish and obsoletely emarginate; cilia whitish, very short and inconspicuous or nearly wanting; capsules aggregated toward the apex; spores 71–84 µ broad, dark fuscous, reticulate, with pellucid margin.—Var. hírta, Aust., decidedly ciliate and with spine-like hairs scattered over the upper surface; divisions broader, more obtuse; spores nearly black, larger (84–101 µ) and smoother.—Cultivated fields and (the var.) rocky places, Closter, N. J. (Austin).

6. R. Lescuriàna, Aust. Stellately or subcruciately divided, the obcordate or cuneate-linear divisions 2–6´´ long, punctate-reticulate, subglaucous or ashy-green both sides or becoming purple beneath, the slightly concave lobes emarginate, closely ciliate with short obtuse spine-like white hairs; capsules scattered, chiefly near the base of the divisions; spores 71–83 µ broad, dark brown, reticulate, not margined.—Cultivated fields and rocky grounds, N. J. to Ill., and southward.

§ 2. SPONGÒDES. Thallus with large air-cavities usually opening by pits through the upper surface, and with slight depressions over the capsules which are prominent beneath; spores 41–51 µ broad, obtusely angular or globose; terrestrial.

7. R. crystállina, L. Orbicular, 6–9´´ broad, the obcordate or cuneate divisions bifid or 2-lobed, flat above and the surface much broken up into pits, the margins subcrenate; capsules scattered; spores issuing through the upper surface.—On mud flats, Ill. (Hall), west and southward. (Eu.)

8. R. lutéscens, Schwein. Orbicular, 1–1½´ in diameter, light green; divisions 6–8, linear, 2–3 times forked, narrowly channelled, obcordate and thickened at the apex, with delicate whitish obliquely ovate appressed scales, rootlets wanting beneath above the middle; fruiting plant unknown.—Dried up pools and ditches, Canada to Mo., and southward. An analogous form has been developed by Lindberg from R. natans.

9. R. ténuis, Aust. Thallus thin, olive or yellowish-green, shining, the 2–4 divisions roundish-obovate, 2–4´´ long, flat, with sinuate margins, green beneath with a slender costa and few rootlets; capsule very delicate, closely adherent to the substance of the thallus, minutely apiculate; spores round or short-oval, conspicuously depressed at one end when dry.—Wet ground in open woods, Closter and Lawrence, N. J. (Austin), and Mo. (Hall).

§ 3. RICCIÉLLA. Thallus linear, dichotomous, floating or rarely terrestrial; capsule protuberant from the lower surface.

10. R. flùitans, L. Thallus often in extended patches, thin, green, radiately expanding, the often imbricate divisions ½–1½´´ wide, parallel-nerved, flat, without rootlets, cavernous only toward the slightly dilated very obtuse or subtruncate apex; capsules present only in some terrestrial forms, very prominent below, rupturing beneath the apex.—Very variable. The most notable form is var. Sullivánti, Aust., with divisions about ½´´ wide, channelled, cavernous throughout, the margins crisped-crenulate, and rootlets numerous on the costa tumid with abundant capsules, which are tipped with a long funnel-mouthed point; spores obscurely angled, reticulate and margined. (R. Sullivanti, Aust.)—In ponds or ditches or growing in wet places upon the ground; the variety often in cultivated fields. (Eu.)

§ 4. RICCIOCÁRPUS. Thallus obcordate, floating or rarely terrestrial; capsules not protruding, at length exposed by a cleft in the central groove.

11. R. nàtans, L. ([Pl. 22.]) Divisions obcordate or cuneate, broadly emarginate, 3–6´´ long, purplish, very narrowly channelled, with numerous uniform air-cavities beneath the epidermis, rooting toward the base and at length with dark purple scales beneath the apex; capsules in 1 or 2 rows beneath the groove; spores black, angular, strongly papillose.—Canada to the Gulf. (Eu.)

2. SPHÆROCÁRPUS, Micheli. ([Pl. 22.])

Thallus lobed, without costa or epidermis. Involucres sessile, obconic or pyriform, perforated at the apex, continuous with the thallus at base. Calyptra closely investing the single globose indehiscent capsule, crowned with a deciduous point. Spores globose, muriculate, remaining united in a coccus. Antheridia borne in follicular bodies on the surface of a separate thallus.—An anomalous genus, perhaps more closely related to the Jungermanniaceæ. (Name from σφαῖρος, a sphere, and καρπός, fruit.)

1. S. terréstris, Smith. Thallus orbicular, 3–6´´ broad, covered by the clustered inflated involucres, which are nearly 1´´ long, 3–4 times the length of the capsule; coccus 102–127 µ wide, indistinctly lobed. (S. Michelii, Bellardi.)—In cultivated fields, mostly southern. (Eu.)