Capsule 1-celled; petals mostly present.

Sepals 2. Fam. 22. Portulacaceae. 2: 35.

Sepals 5 or 4, distinct or united.

Sepals distinct; ovary sessile. Fam. 23. Alsinaceae. 2:41.

Sepals united; ovary stipitate. Fam. 24. Caryophyllaceae. 2: 61.

B. Petals present (wanting in Ceratophyllaceae - aquatic herbs with whorled dissected leaves; in many Ranunculaceae; in Calycocarpum - a dioecious vine of the Menispermaceae; in Laura-ceae - alternate-leaved aromatic trees and shrubs; in Podostemaceae - aquatic herbs, the simple flowers involucrate; in Liquidambar - a tree with palmately-lobed leaves and capitate flowers of the Hamamelidaceae - in Sanguisorba - herbs with pinnate leaves of the Rosaceae; in Xanthoxylum - trees with pinnate leaves of the Rutaceae; in Euphorbiaceae; in Callitrich-aceae, Empetraceae and Buxaceae; in some of the Aceraceae and Rhamnaceae; in Thymele-aceae, Elaeagnaceae, and in some species of Ludwigia in Onagraceae and of Nyssa in Cor-naceae).

I. Ovary superior, free from the calyx (partly or wholly inferior in some Saxifragaceae, in Grossulariaceae, Hamamelidaceae, Malaceae and Loasaceae).

1. Carpels solitary, or several or distinct (united in Nymphaeaceae); stamens mostly hypogynous and more numerous than the sepals; sepals mostly distinct. Order 12. Ran ales.

* Aquatic herbs; floating leaves if present, peltate, or with a basal sinus. Pistil 1; petals none; leaves whorled, dissected. Fam. 25. Ceratophyllaceae. 2: 75.

Carpels 3 or more; petals large; floating leaves not dissected. Carpels distinct.

Carpels not in a receptacle. Fam. 26. Cabombaceae. 2: 75.

Carpels in a fleshy receptacle. Fam. 27. Nelumbonaceae. 2: 76.

Carpels united into a compound ovary. . Fam. 28. Nymphaeaceae. 2: 77.

** Land or marsh plants (some Ranunculaceae aquatic).

Stamens numerous; sepals distinct; petals present (except in some Ranunculaceae and in Calyco-carpum of the Menispermaceae). Receptacle not hollow; leaves alternate (except in Clematis).

Flowers perfect (except in some species of Clematis and Thalictrum).

Fruit aggregate, cone-like; trees; sepals and petals in 3 series, or more, of 3.

Fam. 29. Magnoliaceae. 2: 80. Fruit not aggregate, the carpels separate, at least when mature. - -Anthers not opening by valves; pistils usually more than 1.

Sepals 3; petals 6; shrubs or trees. Fam. 30. Annonaceae. 2: 83.

Sepals 3-15; petals (when present) about as many; our species herbs or vines (Xanthorrhiaa shrubby). Fam. 31. Ranunculaceae. 2:84.

Anthers opening by valves (except in Podophyllum); pistil 1.

Fam. 32. Berberidaceae. 2:126. Dioecious climbing vines with simple leaves; fruit drupaceous.

Fam. 33. Menispermaceae. 2: 130. Receptacle hollow, enclosing the numerous pistils and achenes; opposite-leaved shrubs.

Fam. 34. Calycanthaceae. 2: 132.

Stamens 9 or 12, in 3 or 4 series of 3; anthers opening by valves; aromatic trees or shrubs with no petals, more or less united sepals, and 1 pistil. Fam. 35. Lauraceae. 2: 133.

2. Carpels 2 or more, united into a compound ovary; stamens hypogynous; sepals mostly distinct.

* Plants not insectivorous.

Order 13. Papaverales (Rhoeadales). Sepals 2 (very rarely 3 or 4); endosperm fleshy.

Flowers regular; stamens 8-many. Fam. 36. Papaveraceae. 2: 136.

Flowers irregular; stamens 6. Fam. 37. Fumariaceae. 2: 141.

Sepals or calyx-segments 4-8; endosperm none.

Capsule 2-celled by a longitudinal partition, usually 2-valved, rarely indehiscent; sepals and petals 4. Fam. 38. Cruciferae. 2:146.

Capsule 1-celled, of 2-6 carpels.

Sepals and petals 4, regular, or petals irregular; capsule of 2 carpels, 2-valved.

Fam. 39. Capparidaceae. 2: 196. Sepals and petals 4-8, irregular; capsule of 3-6 carpels, 3-6-valved at the top; disk large.

Fam. 40. Resedaceae. 2:199.

** Insectivorous plants, secreting a viscid liquid, with basal leaves and scapose flowers.

Order 14. Sarraceniales. Ovary 3-5-celled; leaves hollow. Fam. 41. Sarraceniaceae. 2:201.

Ovary 1-celled; leaves circinate in unfolding, the blade flat. Fam. 42. Droseraceae. 2: 202.

3. Carpels solitary, or several and distinct, or sometimes united; stamens mostly perigynous or epigynous; sepals mainly united or confluent with the concave receptacle. Order 15. Rosales.

* Small aquatic fleshy herbs, with a spathe-like involucre, and a 2-3-celled capsule; perianth none.

Fam. 43. Podostemaceae. 2: 205. ** Land or rarely swamp plants without an involucre.

t Endosperm present, usually copious and fleshy.

Herbaceous plants.

Carpels as many as the sepals.

Carpels distinct, or united below, longitudinally dehiscent; succulent plants.

Fam. 44. Crassulaceae. 2: 205. Carpels united to the midlde, circumscissile; plants not succulent.

Fam. 45. Penthoraceae. 2:211. Carpels fewer than the sepals.

Carpels 3 or 4, united into a i-celled ovary; staminodia present.

Fam. 46. Parnassiaceae. 2: 211. Carpels mostly 2, distinct, or only partly united; no staminodia.

Fam. 47. Saxifragaceae. 2:214. Shrubs or trees.

Leaves opposite. Fam. 48. Hydrangeaceae. 2: 230.

Leaves alternate.

Fruit a 2-5-celled capsule.

Capsule thin-walled, almost free from the calyx-tube (hypanthium).

Fam. 49. Iteaceae. 2:233. Capsule woody, or thick-walled, adnate to the calyx-tube.

Ovule solitary, suspended; calyx-limb or calyx-limb and petals present.

Fam. 50. Hamamelidaceae. 2: 234.

Ovules several or numerous; no calyx-limb nor petals. Fam. 51. Altingiaceae. 2:235.

Fruit a i-celled berry. Fam. 52. Grossulariaceae. 2: 236.

tt Endosperm none, or very little (copious in Opulaster, shrubs of the Rosaceae).

X Trees with broad leaves and small monoecious capitate flowers.

Fam. 53. Platanaceae. 2:242.

tt Flowers perfect (dioecious in Aruncus and in species of Fragaria of the Rosaceae; in Gleditsia and Gymnocladus of the Caesalpiniaceae, and rarely in some Fabaceae).