[*] 3. Ovary inferior (except in Pa.s.sifloraceae and Ficoideae), 1-celled with parietal placentae or several-celled by the intrusion of the placentae; flowers regular, perfect or unis.e.xual; styles free or united; herbs.

[+] Embryo straight; cotyledons foliaceous; leaves alternate, often lobed.

43. Loasaceae (p. 193). Flowers perfect. Stamens indefinite. Style entire or 2--3-cleft. Capsule 1-celled, with 2 or 3 many-seeded placentae.

p.u.b.escence of hooked hairs.

44. Pa.s.sifloraceae (p. 194). Climbing by tendrils. Flowers perfect.

Stamens 5, monadelphous. Ovary stalked, superior, becoming a 1-celled many-seeded berry with 3 or 4 placentae. Styles 3, clavate.

45. Cucurbitaceae (p. 194). Tendril-bearing vines, with dicious or moncious flowers. Corolla 5-lobed, often confluent with the calyx.

Stamens 3 or 5, usually more or less united and the anthers often tortuous. Fruit fleshy or membranous, 1--5-celled, the placentae often produced to the axis and revolute. Seeds exalb.u.minous.

[+][+] Embryo curved or coiled about central alb.u.men; leaves entire.

46. Cactaceae (p. 196). Fleshy and mostly leafless p.r.i.c.kly plants, with solitary sessile perfect flowers. Calyx-lobes and petals indefinite, imbricated, the numerous stamens on the tube. Fruit a 1-celled many-seeded berry.

47. Ficoideae (p. 198). Calyx-lobes or sepals 5 and petals none in our genera. Capsule 3--5-celled with axile placentae, loculicidal or circ.u.mscissile, many-seeded. Often fleshy; leaves mostly opposite or verticillate.

[*] 4. Flowers small, regular, perfect or polygamous; calyx-limb minute or obsolete; ovary inferior, 2--several-celled, with solitary pendulous ovules; petals and stamens mostly 4 or 5, on the margin of an epigynous disk surrounding the styles; alb.u.men copious.

48. Umbelliferae (p. 198). Flowers in umbels or heads. Petals (inflexed) and stamens 5. Styles 2. Fruit of 2 dry seed-like carpels, the pericarp usually with oil-tubes. Herbs, with alternate mostly compound leaves.

49. Araliaceae (p. 212). Flowers mostly in umbels and nearly as in Umbelliferae; petals not inflexed and styles 2 or more. Fruit a 2--several-celled drupe. Herbs or shrubs, with alternate mostly compound leaves.

50. Cornaceae (p. 213). Flowers not in umbels; petals (valvate, or none) and stamens 4 or 5. Style 1. Fruit a 1--2-seeded drupe. Trees, shrubs, or rarely herbs, with opposite or alternate simple and mostly entire leaves.

DIVISION II. GAMOPETALOUS: calyx and corolla both present, the latter of united petals (excepting some Ericaceae, Styracaceae, and Oleaceae, Galax, Statice, and Lysimachia). Apetalous flowers occur in Glaux and some Oleaceae. Stipules present only in Rubiaceae and Loganiaceae, or rarely in Caprifoliaceae.

[*] 1. Ovary inferior; stamens borne upon the corolla, alternate with its lobes.

[+] Stamens distinct; leaves opposite or whorled; seed alb.u.minous except in Valerianaceae.

51. Caprifoliaceae (p. 216). Corolla mostly 5-lobed, regular or irregular, the stamens as many (one fewer in Linnaea, doubled in Adoxa). Ovary 1--several-celled; fruit a berry, drupe, or pod, 1--several-seeded. Shrubs or herbs; leaves opposite, rarely stipular, not turning black in drying.

52. Rubiaceae (p. 222). Flowers regular, 4--5-merous, the corolla mostly valvate. Ovary 2--4-celled. Herbs or shrubs; leaves simple, entire, opposite with stipules, or verticillate, usually turning black in drying.

53. Valerianaceae (p. 228). Stamens (1--4) fewer than the lobes of the somewhat irregular corolla. Ovary with two abortive or empty cells and one containing a suspended ovule. Fruit dry and indehiscent. Herbs.

54. Dipsaceae (p. 229). Flowers mostly 4-merous and with 4 (rarely 2) stamens, involucellate in involucrate heads; corolla-lobes imbricate.

Ovary simple, 1-celled, with a suspended ovule. Herbs.

[+][+] Anthers connate into a tube.

55. Compositae (p. 230). Stamens as many as the valvate corolla-lobes.

Ovary with a solitary erect ovule, becoming an achene. Alb.u.men none.

Calyx-limb reduced to a pappus or none. Flowers in involucrate heads.

[*] 2. Ovary inferior (or superior in most Ericaceae and in Diapensiaceae); stamens free from the corolla or nearly so (adnate in some Diapensiaceae), as many as the lobes and alternate with them, or twice as many; leaves alternate (opposite in some Ericaceae); style 1.

[+] Juice milky; capsule 2--5-celled, many-seeded; herbs.

56. Lobeliaceae (p. 305). Corolla irregular, 5-lobed. Stamens united, at least by the anthers. Capsule 2-celled or with two placentae.

57. Campanulaceae (p. 307). Corolla regular, 5-lobed, valvate. Stamens usually distinct. Capsule 2--several-celled.

[+][+] Juice not milky nor acrid; capsule 3--10-celled.

58. Ericaceae (p. 309). Flowers mostly regular, 4--5-merous. Stamens distinct, more usually twice as many as the corolla-lobes or petals.

Ovary inferior or superior. Herbs or shrubs.

59. Diapensiaceae (p. 326). Flowers regular. Stamens 5, on the corolla, or monadelphous with 5 petaloid staminodia. Ovary superior, 3-celled.

[*] 3. Ovary superior; stamens as many as the corolla-lobes and opposite them.

60. Plumbaginaceae (p. 327). Stamens 5, on the base of the petals.

Styles 5. Fruit an achene or 1-seeded utricle. Herbs; leaves radical.

61. Primulaceae (p. 328). Stamens 4--8, perigynous. Style 1. Fruit a capsule with several seeds on a central placenta. Herbs; leaves radical or opposite or alternate.

62. Sapotaceae (p. 332). Flowers small, 4--5-merous. Style 1. Ovary few--several-celled; fruit fleshy, bearing a single bony-coated seed.

Shrubs or trees, with milky juice and alternate entire leaves.

[*] 4. Ovary superior or more or less adnate to the calyx, few--several-celled, the cells 1-ovuled; stamens twice as many as the corolla-lobes or more; trees or shrubs, with alternate leaves.

63. Ebenaceae (p. 333). Flowers dicious or polygamous. Stamens on the corolla. Ovary superior. Styles distinct. Fruit fleshy, few-seeded.

64. Styracaceae (p. 333). Flowers perfect. Stamens subhypogynous. Ovary more or less inferior. Style 1. Fruit dry or nearly so, 1--4-seeded.

[*] 5. Ovary superior, of two carpels (sometimes by division apparently 4-carpellary, sometimes of 3--5 in Polemoniaceae, Convolvulaceae, and Solanaceae); stamens on the corolla (except in apetalous Oleaceae), alternate with its lobes, as many or fewer.

[+] Corolla not scarious and nerveless.

[++] Corolla none, or regular and 4-cleft or -parted, the stamens fewer than its lobes; style 1; seeds 1--3.

65. Oleaceae (p. 335). Trees or shrubs, with opposite and pinnate or simple leaves. Flowers perfect or polygamo-dicious. Stamens mostly 2, alternate with the usually 2-ovuled carpels.

[++][++] Corolla regular, its lobes 4--5 or rarely more; stamens as many.

[=] Ovaries 2, becoming follicles; stigmas and sometimes the styles united; herbs with milky juice, perfect 5-merous flowers, and simple entire leaves.

66. Apocynaceae (p. 337). Stamens distinct or the anthers merely connivent, with ordinary pollen. Style 1.

67. Asclepiadaceae (p. 338). Stamens monadelphous, the anthers permanently attached to a large stigmatic body; pollen mostly in waxy ma.s.ses. Styles distinct below the stigma.

[=][=] Ovary compound (ovaries two in Dichondra), with 2 or 3 (rarely 4 or 5) cells or placentae; stamens distinct; mostly herbs.

[a.] Leaves opposite; corolla-lobes 4 or 5 or more.

68. Loganiaceae (p. 345). Leaves entire, with stipules or a stipular line joining their bases. Capsule 2-celled, few--many-seeded. Herbs or woody twiners (our species).