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