41. Lythraceæ (p. 184). Calyx-lobes valvate. Pod free, but enclosed in the calyx, membranous, 1--4-celled, many-seeded with axile placentæ. Leaves mostly opposite; flowers axillary or whorled; petals crumpled, or none. 42. Onagraceæ (p. 186). Calyx-lobes valvate. Ovary 1--4-celled, the cells 1--many-ovuled. Stamens 2, 4, or 8. Petals 2 or 4, convolute, or none. Leaves opposite or alternate. [*] 3. Ovary inferior (except in Passifloraceæ and Ficoideæ), 1-celled with parietal placentæ or several-celled by the intrusion of the placentæ; flowers regular, perfect or unisexual; styles free or united; herbs. [+] Embryo straight; cotyledons foliaceous; leaves alternate, often lobed. 43. Loasaceæ (p. 193). Flowers perfect. Stamens indefinite. Style entire or 2--3-cleft. Capsule 1-celled, with 2 or 3 many-seeded placentæ. Pubescence of hooked hairs. 44. Passifloraceæ (p. 194). Climbing by tendrils. Flowers perfect. Stamens 5, monadelphous. Ovary stalked, superior, becoming a 1-celled many-seeded berry with 3 or 4 placentæ. Styles 3, clavate. 45. Cucurbitaceæ (p. 194). Tendril-bearing vines, with diœcious or monœcious 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 placentæ often produced to the axis and revolute. Seeds exalbuminous. [+][+] Embryo curved or coiled about central albumen; leaves entire. 46. Cactaceæ (p. 196). Fleshy and mostly leafless prickly 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. Ficoideæ (p. 198). Calyx-lobes or sepals 5 and petals none in our genera. Capsule 3--5-celled with axile placentæ, loculicidal or circumscissile, 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; albumen copious. 48. Umbelliferæ (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. Araliaceæ (p. 212). Flowers mostly in umbels and nearly as in Umbelliferæ; petals not inflexed and styles 2 or more. Fruit a 2--several-celled drupe. Herbs or shrubs, with alternate mostly compound leaves. 50. Cornaceæ (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.