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.)