ANALYTICAL KEY TO THE ORDERS.

Class I. DICOTYLEDONOUS PLANTS. (See p. 1.)

Subclass I. ANGIOSPERMÆ. Pistil consisting of a closed ovary. Cotyledons only two.

Division I. POLYPETALOUS: the calyx and corolla both present; the latter of separate petals.

A. Stamens numerous, at least more than 10, and more than twice the sepals or lobes of the calyx.

1. Calyx entirely free and separate from the pistil or pistils.

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Pistils numerous but cohering over each other in a solid mass on an elongated receptacle. [Magnoliaceæ], [49]

Pistils numerous, separate, but concealed in a hollow receptacle.

Leaves opposite, entire; no stipules. [Calycanthaceæ], [167]

Leaves alternate, with stipules. [Rosa], in [Rosaceæ], [162]

Pistils several, immersed in hollows of the upper surface of a large top-shaped receptacle. [Nelumbo], in [Nymphæaceæ], [55]

Pistils more than one, separate, not enclosed in the receptacle.

Stamens inserted on the calyx, distinct. [Rosaceæ], [150]

Stamens united with the base of the petals, monadelphous. [Malvaceæ], [96]

Stamens inserted on the receptacle.

Filaments much shorter than the anther; trees. [Anonaceæ], [50]

Filaments longer than the anther.

Flowers diœcious; twiners with alternate leaves. [Menispermaceæ], [51]

Flowers perfect; if climbers, the leaves opposite.

Leaves not peltate; petals deciduous. [Ranunculaceæ], [34]

Leaves peltate; petals persistent. [Brasenia], in [Nymphæaceæ], [55]

Pistils several-lobed, the ovaries united below the middle. [Resedaceæ], [75]

Pistils several, their ovaries cohering in a ring around an axis. [Malvaceæ], [96]

Pistils strictly one as to the ovary; the styles or stigmas may be several.

Leaves punctate under a lens with transparent dots. [Hypericaceæ], [92]

Leaves not punctate with transparent dots.

Ovary simple, 1-celled, 2-ovuled. [Rosaceæ], [150]

Ovary simple, 1-celled, with one parietal many-ovuled placenta.

Leaves 2–3-ternately compound or dissected. [Ranunculaceæ], [34]

Leaves peltate, simply lobed. [Podophyllum], in [Berberidaceæ], [52]

Ovary compound, 1-celled, with a central placenta. [Portulacaceæ], [90]

Ovary compound, 1-celled, with two or more parietal placentæ.

Calyx caducous; juice milky or colored. [Papaveraceæ], [57]

Calyx deciduous, of 4 sepals. [Capparidaceæ], [74]

Calyx persistent, of 3 or 5 sepals. [Cistaceæ], [76]

Ovary compound, several-celled.

Calyx valvate in the bud, and

Persistent; stamens monadelphous; anthers 1-celled. [Malvaceæ], [96]

Deciduous; anthers 2-celled. [Tiliaceæ], [101]

Calyx imbricated in the bud, persistent.

Shrubs; stamens on the base of the petals. [Ternstrœmiaceæ], [95]

Aquatic or marsh herbs; ovaries many,

On 5 placentæ in the axis. [Sarraceniaceæ], [57]

On the 8–30 partitions. [Nymphæaceæ], [54]

2. Calyx more or less coherent with the surface of the (compound) ovary.

Ovary 8–30-celled; ovules many, on the partitions; aquatic. [Nymphæaceæ], [54]

Ovary 10-celled; cells 1-ovuled. [Amelanchier], in [Rosaceæ], [166]

Ovary 2–5-celled.

Leaves alternate, with stipules. Pomeæ, in [Rosaceæ], [151]

Leaves opposite, without stipules. Some [Saxifragaceæ], [168]

Leaves alternate, without stipules. [Styracaceæ], [333]

Ovary 1-celled, with the ovules parietal.

Fleshy plants with no true foliage; petals many. [Cactaceæ], [186]

Rough-leaved plants; petals 5 or 10. [Loasaceæ], [193]

Ovary one-celled, with the ovules rising from the base. [Portulacaceæ], [90]

B. Stamens of the same number as the petals and opposite them.

Pistils 3–6, separate; flowers diœcious; woody vines. [Menispermaceæ], [51]

Pistil only one.

Ovary one-celled; anthers opening by uplifted valves. [Berberidaceæ], [52]

Ovary one-celled; anthers not opening by uplifted valves.

Style and stigma one; ovules more than one. [Primulaceæ], [328]

Style 1; stigmas 3; sepals 2; ovules several. [Portulacaceæ], [90]

Style twice or thrice forked; flowers monœcious. [Crotonopsis], in [Euphorbiaceæ], [458]

Styles 5; ovule and seed only one. [Plumbaginaceæ], [327]

Ovary 2–4-celled.

Calyx-lobes minute or obsolete; petals valvate. [Vitaceæ], [112]

Calyx 4–5-cleft, valvate in the bud; petals involute. [Rhamnaceæ], [111]

C. Stamens not more than twice as many as the petals, when of just the number of the petals then alternate with them.

1. Calyx free from the ovary, i.e. the ovary wholly superior.

[*] Ovaries 2 or more, separate.

Stamens united with each other and with a large and thick stigma common to the two ovaries. [Asclepiadaceæ], [338]

Stamens unconnected, on the receptacle, free from the calyx.

Leaves punctate with pellucid dots. [Rutaceæ], [106]

Leaves not pellucid-punctate.

Tree, with pinnate leaves. [Ailanthus], in Simarubaceæ, [107]

Low shrub, with pinnate leaves. [Xanthorrhiza], in [Ranunculaceæ], [48]

Herbs, not fleshy. [Ranunculaceæ], [34]

Herbs, with thick fleshy leaves. [Crassulaceæ], [176]

Stamens unconnected, inserted on the calyx.

Just twice as many as the pistils (flower symmetrical). [Crassulaceæ], [176]

Not just the number or twice the number of the pistils.

Leaves without stipules. [Saxifragaceæ], [168]

Leaves with stipules. [Rosaceæ], [150]

[*][*] Ovaries 2–5, somewhat united at the base, separate above.

Leaves punctate with pellucid dots. [Rutaceæ], [106]

Leaves not pellucid-punctate.

Shrubs or trees with opposite leaves. [Sapindaceæ], [115]

Terrestrial herbs; the carpels fewer than the petals. [Saxifragaceæ], [168]

[*][*][*] Ovaries or lobes of ovary 3 to 5, with a common style. [Geraniaceæ], [102]

[*][*][*][*] Ovary only one, and

[+] Simple, with one parietal placenta. [Leguminosæ], [122]

[+][+] Compound, as shown by the number of cells, placentæ, styles, or stigmas.

Ovary one-celled.

Corolla irregular; petals 4; stamens 6. [Fumariaceæ], [59]

Corolla irregular; petals and stamens 5. [Violaceæ], [78]

Corolla regular or nearly so.

Ovule solitary; shrubs or trees; stigmas 3. [Anacardiaceæ], [118]

Ovules solitary or few; herbs. Some anomalous [Cruciferæ], [61]

Ovules more than one, in the centre or bottom of the cell.

Petals not inserted on the calyx. [Caryophyllaceæ], [82]

Petals on the throat of a bell-shaped or tubular calyx. [Lythraceæ], [184]

Ovules several or many, on two or more parietal placentæ.

Leaves punctate with pellucid and dark dots. [Hypericaceæ], [92]

Leaves beset with reddish gland-tipped bristles. [Droseraceæ], [178]

Leaves neither punctate nor bristly-glandular.

Sepals 5, very unequal or only 3. [Cistaceæ], [76]

Sepals and petals 4; stamens 6. Anomalous [Cruciferæ], [61]

Sepals and petals 5; stamens 5 or 10.

Ovary and stamens raised on a stalk. [Passifloraceæ], [194]

Ovary sessile. [Saxifragaceæ], [168]

Ovary 2–several-celled.

Flowers irregular.

Anthers opening at the top,

Six or eight and 1-celled; ovary 2-celled, 2-ovuled. [Polygalaceæ], [120]

Ten and 2-celled; ovary 5-celled. [Rhododendron], in [Ericaceæ], [286]

Anthers opening lengthwise.

Stamens 12 and petals 6 on the throat of a tubular inflated or gibbous calyx. [Cuphea], in [Lythraceæ], [186]

Stamens 5–8 or 10, and petals hypogynous, or nearly so.

Ovary 3-celled. [Sapindaceæ], [115]

Ovary 5-celled. [Impatiens], &c., in [Geraniaceæ], [105]

Flowers regular or nearly so.

Stamens neither just as many nor twice as many as the petals,

Triadelphous; petals 5. [Hypericaceæ], [92]

Tetradynamous (or rarely only 2 or 4); petals 4; pungent herbs. [Cruciferæ], [61]

Distinct and fewer than the 4 petals. [Oleaceæ], [335]

Distinct and more numerous than the petals. [Sapindaceæ], [115]

Stamens just as many or twice as many as the petals.

Ovules and seeds only 1 or 2 in each cell.

Herbs; flowers monœcious or diœcious. [Euphorbiaceæ], [451]

Herbs; flowers perfect and symmetrical.

Cells of the ovary as many as the sepals, &c. [Geraniaceæ], [102]

Cells of the (divided) ovary twice as many as the styles, sepals, &c. [Linaceæ], [101]

Shrubs or trees.

Leaves 3-foliolate, pellucid-punctate. [Ptelea], in [Rutaceæ], [107]

Leaves palmately veined and fruit 2-winged, or pinnate and fruit a berry. [Sapindaceæ], [115]

Leaves pinnately veined, simple, not punctate.

Calyx not minute; pod colored, dehiscent; seeds enclosed in a pulpy aril. [Celastraceæ], [109]

Calyx minute; fruit a berry-like drupe. [Ilicineæ], [107]

Ovules (and usually seeds) several or many in each cell.

Stipules between the opposite and simple leaves. [Elatinaceæ], [91]

Stipules between the opposite and compound leaves (but they are caducous). [Staphylea], in [Sapindaceæ], [118]

Stipules none when the leaves are opposite.

Stamens 5, monadelphous in a 10-toothed tube or cup; leaves simple, all radical. [Galax], in [Diapensiaceæ], [326]

Stamens 10, monadelphous at the base. Leaflets 3, inversely heart-shaped. [Oxalis], in [Geraniaceæ], [105]

Stamens distinct, free from the calyx.

Style 1, undivided. [Ericaceæ], [303]

Styles 2–5, separate. [Caryophyllaceæ], [82]

Stamens distinct, inserted on the calyx.

Styles 2 (or 3), or splitting into 2 in fruit. [Saxifragaceæ], [168]

Style 1; pod in the calyx, 1-celled. [Lythraceæ], [184]

2. Calyx-tube adherent to the ovary, at least to its lower half.

Tendril-bearing and often succulent herbs. [Cucurbitaceæ], [194]

Not tendril-bearing.

Ovules and seeds more than one in each cell.

Ovary 1-celled, many-ovuled from the base. [Portulacaceæ], [90]

Ovary 1-celled, with 2 or 3 parietal placentæ. [Saxifragaceæ], [168]

Ovary 2–several-celled.

Anthers opening by pores at the apex; style 1. [Melastomaceæ], [183]

Anthers not opening by pores.

Stamens on a flat disk which covers the ovary. [Celastraceæ], [109]

Stamens inserted on the calyx.

Eight or four (rarely five); style 1. [Onagraceæ], [186]

Five or ten; styles 2–3, distinct. [Saxifragaceæ], [168]

Ovules and seeds only one in each cell.

Stamens 10 or 5 (instead of many),— rarely in [Cratægus], in [Rosaceæ], [165]

Stamens 2 or 8; style 1; stigma 2–4-lobed; herbs. [Onagraceæ], [186]

Stamens 4 or 8; aquatics; styles or sessile stigmas 4. [Halorageæ], [180]

Perfect stamens 4; styles 2; shrub. [Hamamelideæ], [179]

Stamens 4; style and stigma 1; chiefly shrubs. [Cornaceæ], [213]

Stamens 5; flowers in umbels, or rarely in heads.

Fruit dry, splitting in two at maturity; styles 2. [Umbelliferæ], [193]

Fruit berry-like; styles 2–5, separate or united. [Araliaceæ], [212]

Division II. GAMOPETALOUS calyx and corolla both present; the latter with its petals united more or less into one piece.

A. Stamens more numerous than the lobes of the corolla.

Ovary 1-celled with one parietal placenta. [Leguminosæ], [122]

Ovary 1-celled with two parietal placentæ. [Adlumia], &c., in [Fumariaceæ], [60]

Ovary 1-celled with the ovules at the centre or base. [Styracaceæ], [333]

Ovary 2-celled with a single ovule in each cell. [Polygalaceæ], [120]

Ovary 3–many-celled.

Stamens free or nearly free from the corolla; style single. [Ericaceæ], [309]

Stamens free from the corolla; styles 5. [Oxalis], in [Geraniaceæ], [105]

Stamens inserted on the base or tube of the corolla.

Filaments monadelphous; anthers 1-celled, kidney-shaped. [Malvaceæ], [96]

Filaments 1–5-adelphous at base; anthers 2-celled.

Calyx free from the ovary. [Ternstrœmiaceæ], [96]

Calyx coherent with the ovary or with its base. [Styracaceæ], [333]

Filaments wholly distinct; calyx free, persistent. [Ebenaceæ], [333]

Filaments in pairs at each sinus; anthers 1-celled. [Caprifoliaceæ], [216]

B. Stamens (fertile ones) as many as the lobes of the corolla and opposite them.

Ovary 5-celled; corolla appendaged with scales inside. [Sapotaceæ], [332]

Ovary 1-celled; pod several–many-seeded; style 1. [Primulaceæ], [328]

Ovary 1-celled; utricle 1-seeded; styles 5. [Plumbaginaceæ], [327]

C. Stamens as many as the lobes of the corolla and alternate with them, or fewer.

1. Ovary adherent to the calyx-tube (inferior).

Tendril-bearing herbs; anthers often united. [Cucurbitaceæ], [194]

Tendrils none.

Stamens united by their anthers into a ring or tube.

Flowers in an involucrate head. [Compositæ], [230]

Flowers separate, not involucrate; corolla irregular. [Lobeliaceæ], [305]

Stamens separate, free from the corolla or nearly so, as many as its lobes; stipules none; juice milky. [Campanulaceæ], [307]

Stamens separate, inserted on the corolla,

One to three, always fewer than the corolla-lobes. [Valerianaceæ], [228]

Four or five; leaves opposite or whorled.

Ovary 1-celled; flowers in a dense involucrate head. [Dipsaceæ], [229]

Ovary 2–5-celled.

Leaves whorled and without stipules. [Rubiaceæ], [222]

Leaves opposite or whorled, and with stipules. [Rubiaceæ], [222]

Leaves opposite without stipules (petioles sometimes with stipule-like appendages). [Caprifoliaceæ], [216]

2. Ovary free from the calyx (superior).

[*] Corolla irregular; stamens (with anthers) 4 and didynamous, or only 2.

Ovules and seeds solitary in the (1–4) cells.

Ovary 4-lobed, the style rising from between the lobes. [Labiatæ], [403]

Ovary not lobed, the style from its apex. [Verbenaceæ], [401]

Ovules numerous or at least as many as 2 in each cell.

Ovary and pod 1-celled,

With a free central placenta; stamens 2. [Lentibulaceæ], [395]

With 2 or more parietal very many-seeded placentæ; stamens 4. [Orobanchaceæ], [393]

Ovary and fruit more or less 4–5-celled. [Pedaliaceæ], [399]

Ovary and pod 2-celled, but the 2 placentæ parietal. [Bignoniaceæ], [398]

Ovary and pod 2-celled; placentæ in the axis.

Seeds rarely few, not on hooks, with albumen. [Scrophulariaceæ], [377]

Seeds few, borne on hook-like or other projections of the placentæ; no albumen. [Acanthaceæ], [399]

[*][*] Corolla somewhat irregular; stamens (with anthers) 5.

Stamens free from the corolla; anthers with their cells opening by a hole or chink at the top. [Rhododendron], in [Ericaceæ], [320]

Stamens inserted on the corolla.

Ovary deeply 4-lobed around the style. [Echium], in [Borraginaceæ], [367]

Ovary not lobed; pod many-seeded.

Filaments or some of them woolly. [Verbascum], [Scrophulariaceæ], [379]

Filaments not woolly. [Hyoscyamus], [Solanaceæ], [376]

[*][*][*] Corolla regular.

[+] Stamens as many as the lobes of the corolla.

Ovaries 2, separate; their

Styles and stigmas also wholly separate. [Dichondra], [Convolvulaceæ], [368]

Stigmas and sometimes styles united into one.

Filaments distinct; pollen in ordinary grains. [Apocynaceæ], [337]

Filaments monadelphous; pollen in masses. [Asclepiadaceæ], [338]

Ovary one, but deeply 4-lobed around the style (or 2-lobed in Heliotropium).

Leaves alternate. [Borraginaceæ], [360]

Leaves opposite. [Mentha], in [Labiatæ], [407]

Ovary one; pod 2-lobed or 2-horned at the summit. [Loganiaceæ], [345]

Ovary one; not deeply lobed,

One-celled, one-ovuled, becoming an achene. [Plantaginaceæ], [422]

One-celled, with ovules parietal or on 2 parietal placentæ.

Leaves (or in Menyanthes three leaflets) entire. [Gentianaceæ], [346]

Leaves toothed, lobed, or pinnately compound. [Hydrophyllaceæ], [357]

Two- to ten-celled.

Leafless parasitic twining plants. [Cuscuta], in [Convolvulaceæ], [370]

Leaves opposite, their bases or petioles connected by stipules or a stipular line. [Loganiaceæ], [345]

Leaves when opposite without stipules.

Stamens free from the corolla or nearly so; style 1. [Ericaceæ], [309]

Stamens almost free from the corolla; style none. [Ilicineæ], [107]

Stamens in the sinuses of the corolla; style 1. [Diapensiaceæ], [326]

Stamens inserted on the tube of the corolla,

Four; pod 2-celled, circumscissile. [Plantaginaceæ], [422]

Four; ovary 2–4-celled; ovules solitary. [Verbenaceæ], [401]

Five or rarely more.

Fruit of two or four seed-like nutlets. [Borraginaceæ], [360]

Fruit a few-seeded pod.

Calyx 5-cleft; style 3-lobed or -cleft. [Polemoniaceæ], [354]

Sepals 5; styles 1 or 2, entire or 2-cleft; seeds large, only one or two in a cell. [Convolvulaceæ], [367]

Fruit a many-seeded pod or berry.

Styles 2. [Hydrolea], in [Hydrophyllaceæ], [360]

Style single. [Solanaceæ], [373]

[+][+] Stamens fewer than the lobes of the corolla.

Stamens 4, didynamous.

Ovary 2-celled; the cells several-seeded. [Acanthaceæ], [399]

Ovary 2–4-celled; the cells 1-seeded. [Verbenaceæ], [401]

Stamens only 2 with anthers; ovary 4-lobed. [Lycopus], in [Labiatæ], [408]

Stamens 2, rarely 3; ovary 2-celled.

Low herbs; corolla scarious, withering on the pod. [Plantaginaceæ], [422]

Herbs; corolla rotate, or somewhat funnelform, and slightly irregular. [Veronica], in [Scrophulariaceæ], [386]

Shrubs or trees; corolla perfectly regular. [Oleaceæ], [335]

Division III. APETALOUS: corolla (and sometimes calyx) wanting.

A. Flowers not in catkins.

1. Ovary or its cells containing many ovules.

Ovary and pod inferior (i.e. calyx-tube adherent to the ovary),

Six-celled; stamens 6–12. [Aristolochiaceæ], [444]

Four-celled; stamens 4. [Ludwigia], in [Onagraceæ], [187]

One-celled, with parietal placentæ. [Chrysosplenium], in [Saxifragaceæ], [172]

Ovary and pod wholly naked (there being no calyx),

Two-celled, 2-beaked; flowers capitate; tree. [Hamamelideæ], [179]

Two-celled, many-ribbed; aquatic herb. [Podostemaceæ], [444]

Ovary and pod superior, i.e. free from the calyx.

Five-celled and 5-beaked, opening across the beaks, which fall off at maturity; stamens 10. [Penthorum], in [Crassulaceæ], [176]

Three-celled and 3-valved, or 3–5-celled and circumscissile. [Ficoideæ], [198]

Two-celled or one-celled; placentæ central.

Stamens inserted on the throat or tube of the calyx. [Lythraceæ], [184]

Stamens inserted on the receptacle or the base of the calyx,

Alternate with the 5 sepals. [Glaux], in [Primulaceæ], [331]

Opposite the sepals when of the same number. [Caryophyllaceæ], [82]

One-celled, with one parietal placenta. [Ranunculaceæ], [34]

Ovaries 2 or more, separate, simple. [Ranunculaceæ], [34]

2. Ovary or its cells containing only 1 or 2, rarely 3 or 4, ovules.

[*] Pistils more than one, and distinct or nearly so.

Stamens inserted on the calyx; leaves with stipules. [Rosaceæ], [150]

Stamens inserted on the receptacle.

Leaves punctate with pellucid dots. [Xanthoxylum], in [Rutaceæ], [106]

Leaves not dotted.

Calyx present, and usually colored or petal-like. [Ranunculaceæ], [34]

Calyx absent; flowers entirely naked, perfect, spiked. [Piperaceæ], [446]

[*][*] Pistil one, either simple or compound.

Ovary partly inferior, the calyx coherent to its lower half, 2-celled; styles 2; stamens many. [Hamamelideæ], [179]

Ovary wholly inferior (in perfect or pistillate flowers).

Aquatic herbs; ovary 3–4-celled, or (Hippuris) 1-celled. [Halorageæ], [180]

Mostly woody plants; style or stigma one, entire; ovary 1-celled.

Stigma running down one side of the style. [Nyssa], in [Cornaceæ], [215]

Stigma terminal, with or without a style.

Parasitic on the branches of trees; anthers sessile. [Loranthaceæ], [449]

Not parasitic above ground; anthers on filaments. [Santalaceæ], [450]

Ovary really free from the calyx, but permanently invested by its tube, or the base of it, so as to seem inferior.

Shrubs, with scurfy leaves; flowers mostly diœcious. [Elæagnaceæ], [448]

Herbs, with the calyx colored like a corolla.

Leaves opposite, simple. [Nyctaginaceæ], [425]

Leaves alternate, pinnate. [Poterium], in [Rosaceæ], [161]

Ovary plainly free from the calyx, which is sometimes wanting.

Stipules (ocreæ) sheathing the stem at the nodes.

Tree; calyx none; flowers monœcious, in heads. [Platanaceæ], [466]

Herbs; calyx present and commonly petal-like. [Polygonaceæ], [436]

Stipules not sheathing the stem, or none.

Aquatic herbs, submerged or nearly so.

Leaves whorled and dissected; style single. [Ceratophyllaceæ], [488]

Leaves opposite, entire; styles 2; ovary 4-celled. [Halorageæ], [180]

Not aquatics, herbs.

Ovary 10-celled; berry 10-seeded. [Phytolaccaceæ], [436]

Ovary 3- (rarely 1–2-) celled; juice usually milky. [Euphorbiaceæ], [451]

Ovary 1-celled; juice not milky.

Style, if any, and stigma only one; leaves simple; no scarious bracts around the flowers. [Urticaceæ], [461]

Styles 3; embryo straight; flowers involucrate. [Eriogonum], in [Polygonaceæ], [436]

Style or stigmas 2 or 3; embryo coiled or curved.

Stipules not scarious, leaves palmately cleft or palmately compound. Cannabineæ, in [Urticaceæ], [461]

Stipules scarious (or none); leaves opposite. [Illecebraceæ], [426]

Stipules none; but flowers with scarious bracts. [Amarantaceæ], [427]

Stipules and scarious bracts none. [Chenopodiaceæ], [430]

Shrubs or trees.

Ovules a pair in each cell of the ovary.

Fruit 2-celled, a double samara. Acerineæ, in [Sapindaceæ], [115]

Fruit a 1-celled and 1-seeded samara or a drupe. [Oleaceæ], [335]

Ovules single in each cell of the

Three-nine-celled ovary; leaves heath-like. [Empetraceæ], [487]

Three-celled ovary; leaves broad. [Rhamnaceæ], [111]

One–two-celled ovary; styles or stigmas 2-cleft. [Urticaceæ], [461]

One-celled ovary; style and stigma single and entire.

Anthers opening longitudinally. [Thymelæaceæ], [448]

Anthers opening by uplifted valves. [Lauraceæ], [446]

B. Flowers monœcious or diœcious, one or both sorts in catkins.

1. Only one sort of flowers in catkins or catkin-like heads.

Fertile flowers in a short catkin, head, or strobile. [Urticaceæ], [461]

Fertile flowers single or clustered; sterile in slender catkins (except in Fagus).

Leaves pinnate; fertile flowers and fruit naked. [Juglandaceæ], [467]

Leaves simple; fertile flowers 1–3 in an involucre or cup. [Cupuliferæ], [470]

2. Both sterile and fertile flowers in catkins or catkin-like heads.

Ovary and pod 2-celled, many-seeded. [Liquidambar], in [Hamamelideæ], [180]

Ovary and pod 1-celled, many-seeded; seeds furnished with a downy tuft at one end. [Salicaceæ], [480]

Ovary 1–2-celled, only one ovule in each cell; fruit 1-seeded.

Parasitic on trees; fruit a berry. [Loranthaceæ], [449]

Trees or shrubs, not parasitic.

Calyx regular, in the fertile flower succulent in fruit. [Urticaceæ], [461]

Calyx none, or rudimentary and scale-like.

Style and stigma one, simple; the flowers in heads. [Platanaceæ], [466]

Styles or long stigmas 2.

Fertile flowers 2 or 3 at each scale of the catkin. [Cupuliferæ], [470]

Fertile flowers single under each scale; nutlets naked, waxy-coated or drupe like. [Myricaceæ], [469]

Subclass II. GYMNOSPERMÆ. Pistil an open scale or altered leaf, bearing naked ovules on its margin or its upper surface, or in Taxus entirely wanting. Flowers monœcious or diœcious. [Coniferæ], [489]

Class II. MONOCOTYLEDONOUS PLANTS. (See [p. 15.])

A. Spadiceous Division. Flowers aggregated on a spadix or fleshy axis, or sometimes scattered, destitute of calyx and corolla (excepting some Araceæ and Naiadaceæ, where, however, they are on a spadix), and also without glumes (husky scales). Leaves sometimes with netted veins.

Little floating aquatics, with no distinction of stem and foliage. [Lemnaceæ], [551]

Immersed aquatics, branching and leafy. [Naiadaceæ], [557]

Reed-like or Flag-like marsh herbs, with linear and sessile nerved leaves; flowers in spikes or heads.

Flowers monœcious, and quite destitute of floral envelopes. [Typhaceæ], [547]

Flowers perfect, on a lateral spadix; sepals 6. [Acorus], in [Araceæ], [550]

Terrestrial or marsh plants; leaves mostly with a distinct netted-veined blade, petioled. [Araceæ], [548]

B. Petaloideous Division. Flowers not collected on a spadix, furnished with floral envelopes (perianth) answering to calyx or to both calyx and corolla, either herbaceous or colored and petal-like (wholly glumaceous in Juncaceæ).

1. Perianth adherent to the whole surface of the ovary.

Flowers diœcious (or rarely perfect), regular.

Aquatics; ovules and seeds several or numerous. [Hydrocharidaceæ], [495]

Twiners; ovules and seeds one or two in each cell. [Dioscoreaceæ], [517]

Flowers perfect; ovules and seeds usually numerous.

Stamens only one or two; flower irregular, gynandrous. [Orchidaceæ], [497]

Stamens three.

Anthers introrse, opening transversely. [Burmanniaceæ], [496]

Anthers introrse or versatile, opening lengthwise. [Hæmodoraceæ], [512]

Anthers extrorse, opening lengthwise. [Iridaceæ], [513]

Stamens 6; flowers usually on a scape from a bulb. [Amaryllidaceæ], [515]

2. Perianth adherent only to the base or lower half of the ovary.

Perianth woolly or roughish-mealy; leaves often equitant. [Hæmodoraceæ], [512]

Perianth smooth; the leaves grass-like. [Stenanthium], etc., in [Liliaceæ], [517]

3. Perianth wholly free from the ovary.

Pistils numerous or few in a head or ring. [Alismaceæ], [553]

Pistil one, compound (cells or placentæ mostly 3).

Perianth not glumaceous or chaffy; flowers not in dense heads.

Stamens 6 (in Maianthemum 4), similar and perfect.

Scurfy-leaved epiphyte; seeds hairy-tufted. [Bromeliaceæ], [511]

Marsh herbs; carpels nearly distinct or separating closed from the axis; seed without albumen. Juncagineæ, in [Naiadaceæ], [557]

Terrestrial, not rush-like; seeds with albumen.

Perianth of similar divisions or lobes, mostly colored. [Liliaceæ], [517]

Perianth of 3 foliaceous and green sepals and 3 colored withering-persistent petals. [Trillium] in [Liliaceæ], [517]

Perianth of 3 persistent green sepals, and 3 ephemeral deliquescent petals. [Commelinaceæ], [538]

Stamens 6, dissimilar, or only three with perfect anthers.

Sepals 3, herbaceous; ephemeral petals 3, unequal. [Commelinaceæ], [538]

Perianth tubular, 6-lobed. [Pontederiaceæ], [535]

Stamens 3, similar. Moss-like aquatic. [Mayaceæ], [537]

Perianth wholly glumaceous, of 6 similar divisions. [Juncaceæ], [539]

Perianth partly glumaceous or chaff-like; flowers in very dense heads. Rush-like or aquatic.

Flowers perfect; inner perianth of three yellow petals; perfect stamens and plumose sterile filaments each 3; pod 1-celled, many-seeded on 3 parietal placentæ. [Xyridaceæ], [536]

Flowers monœcious or diœcious, whitish-bearded; stamens 4 or 3; pod 2–3-celled, 2–3-seeded. [Eriocauleæ], [566]

C. Glumaceous Division. Flowers destitute of proper perianth, except sometimes small scales or bristles, but covered by scale-like bracts or glumes.

Glume a single scale-like bract with a flower in its axil. [Cyperaceæ], [567]

Glumes in pairs, of two sorts. [Gramineæ], [623]

Class III. CRYPTOGAMOUS ACROGENS. (See [p. 17.])

Subclass I. PTERIDOPHYTES: with woody fibres and vessels.

Spores of only one kind; spore-cases

Borne beneath shield-shaped scales in a terminal spike; stems naked, sheathed at the nodes. [Equisetaceæ], [675]

On the back or margin of fronds circinate in vernation. [Filices], [678]

Bivalvular, in special spikes or panicles; fronds erect in vernation, from short erect rootstocks. [Ophioglossaceæ], [693]

Solitary in the axils of leaves, 2–3-valved; low long-stemmed moss-like evergreens; leaves small, in 4–16 ranks. [Lycopodiaceæ], [695]

Spores of two kinds, large and small; spore-cases

Solitary in the axils of small 4-ranked leaves, or in the bases of linear radical leaves. [Selaginellaceæ], [697]

Enclosed in peduncled sporocarps; leaves 4-foliolate. [Marsiliaceæ], [700]

Sporocarps sessile beneath the stem; small, floating, pinnately branched, with minute imbricate leaves. [Salviniaceæ], [701]

Subclass II. BRYOPHYTES: with cellular tissue only. [Capsules not operculate, containing spores and usually elaters, in the following Orders.]

Capsule 4-valved, pedicellate; plants leafy-stemmed, rarely thallose. [Jungermanniaceæ], [702]

Capsule 2-valved or valveless; plants thallose.

Thallus without epidermis; capsule with a columella, short-pedicelled or sessile on the thallus. [Anthocerotaceæ], [726]

Capsules borne beneath a pedunculate receptacle. [Marchantiaceæ], [727]

Capsules immersed in the thallus or sessile upon it, indehiscent. [Ricciaceæ], [730]

ABBREVIATIONS
OF THE NAMES OF AUTHORS CITED IN THIS VOLUME.