Epiphytes; leaves scurfy. Fam. 17. Bromeliaceae. 1: 456.

Terrestrial or aquatic herbs; leaves not scurfy.

Perianth of 2 series of parts, the outer (sepals) green, the inner (petals) colored.

Fam. 18. CommeJinaceae. 1: 457. Perianth 6-parted. Fam. 19. Pontederiaceae. 1: 462.

tt Endosperm fleshy or horny; ovary superior or inferior.

Order 10. Liliales.

a. Ovary superior (except in Aletris, in the Liliaceae, and some species of Zygadenus in the Melanthaceae). Perianth-segments distinct, green or brown, not petal-like; herbs with grass-like leaves and small flowers. Fam. 20. Juncaceae. 1: 465.

Perianth-segments distinct, or partly united, at least the inner petal-like.

Fruit a capsule (except in Yucca baccata, where it is large, fleshy and indehiscent).

Capsule mostly septicidal; plants rarely bulbous. Fam. 21. Melanthaceae. 1: 485.

Capsule loculicidal (septicidal in Calochortus); plants mostly bulbous.

Fam. 22. Liliaceae. 1: 495. Fruit a fleshy berry (except in Uvularia of the Convallariaceae). Erect herbs; tendrils none; flowers perfect.

Leaves basal or alternate. Fam. 23. Convallariaceae. 1:513.

Leaves verticillate. Fam. 24. Trilliaceae. 1: 522.

Vines, climbing by tendrils, or rarely erect; flowers dioecious, in axillary umbels.

Fam. 25. Smilaceae. 1: 526.

b. Ovary inferior, wholly or in part.

Stamens 3, opposite the inner corolla-segments. Fam. 26. Haemodoraceae. 1: 530. Stamens 6 in our species.

Erect perennial herbs; flowers perfect. Fam. 27. Amaryllidaceae. 1: 531.

Twining vines; flowers dioecious. Fam. 28. Dioscoraceae. 1: 535.

Stamens 3, opposite the outer corolla-segments. Fam. 29. Iridaceae. 1: 536.

tt Flowers very irregular; ovary inferior.

Order 11. Scitaminales. One family represented in our territory. Fam. 30. Marantaceae. 1: 546.

** Seeds without endosperm,very numerous and minute; ovary inferior.

Order. 12. Orchidales (Microspermae). Flowers regular; stem-leaves reduced to scales. Fam. 31. Burmanniaceae. 1: 546.

Flowers very irregular. Fam. 32. Orchidaceae. 1: 547.

Subclass 2. Dicotyledones. i: 577.

Embryo normally with 2 cotyledoxes; stems mostly differentiated into pith, wood and bark; leaves mostly net-veined.

Series 1. Choripetalae. i: 577 to a: 666. Petals distinct to the base, or wanting (exceptions noted Vol. 1: 577). A. Petals none, except in Portulacaceae and in most Caryophyllaceae, which are herbs with leaves nearly always opposite, the seeds with endosperm, and in the pistillate flowers of the walnuts (Juglans).

1. Calyx none (except in the Juglandaceae, which are trees with odd-pinnate leaves). Marsh herbs with perfect flowers in nodding spikes. Order 1. Piperales.

One family only.

Fam. 1. Saururaceae. 1: 577. Trees or shrubs; staminate flowers, and sometimes also the pistillate, in aments.

Leaves odd-pinnate; fruit a nut enclosed in a husk. Order 2. Juglandales.

One family only.

Fam. 2. Juglandaceae. 1: 578. Leaves simple.

Fruit 1-seeded. Order 3. Myricales.

Ovule erect, orthotropous. Fam. 3. Myricaccae. 1: 584.

Ovule laterally attached, ascending, amphitropous. Fam. 4. Leitneriaceae. 1: 586.

Fruit many-seeded; seeds with a tuft of hairs at one end. Order 4. Salicales.

One family only.

Fam. 5. Salicaceae. 1: 587. 2. Calyx present. * Flowers, at least the staminate ones, in aments.

Order 5. Fagales. Both staminate and pistillate flowers in aments. Fam. 6. Betulaceae. 1: 605.

Pistillate flowers subtended by an involucre, which becomes a bur or a cup in fruit.

Fam. 7. Fagaceae. 1:614. ** Flowers not in aments (in ament-like spikes in Morus), but variously clustered, rarely solitary.

a. Flowers monoecious, dioecious or polygamous (sometimes perfect in Ulmus); ovary superior, 1-celled.

Order 6. Urticales. Fruit not an achene; trees, shrubs or herbs; ovule pendulous.

Trees with alternate leaves, the sap not milky. Fam. 8. Uhnaceae. 1: 625.

Trees with alternate leaves and milky sap. Fam. 9. Moraceae. 1: 630.

Fruit an achene; herbs with small clustered greenish flowers.

Ovule pendulous; styles or stigmas 2. Fam. 10. Cannabinaceae. 1: 633.

Ovule erect or ascending; style or stigma 1. Fam. 11. Urticaceae. 1: 634.

(Order 7, Proteales, extensively developed in the southern hemisphere, is not represented in our area.) b. Flowers dioecious, or perfect; ovary inferior, at least in part. Ovary i-celled. Order 8. Santalales.

Tree-parasites, with opposite leaves or scales; fruit a berry. Fam. 12. Loranthaceae. 1: 638.

Root-parasites, or shrubs; leaves alternate in our genera; fruit a drupe, or nut.

Fam. 13. Santalaceae. 1: 639. Ovary several- (usually 6-) celled; flowers perfect. Order 9. Aristolochiales.

One family in our area.

Fam. 14. Aristolochiaceae. 1: 641. C. Flowers mostly perfect in our genera (dioecious in some species of Rumex in Polygonaceae, monoecious or dioecious in some Chenopodiaceae and Amaranthaceae); ovary superior.

t Embryo straight, or nearly so; fruit an achene.

Order 10. Polygonales. One family.

Fam. 15. Polygonaceae. 1: 646.

tt Embryo coiled, curved, or annular; fruit not an achene.

Order 11. Chenopodiales (Centrospermae). Fruit a utricle; stipules none

Bracts and sepals scarious. Fam. 16. Amaranthaceae. 2: 1.

Bracts none, or not scarious. Fam. 17. Chenopodiaceae. 2: 8.

Fruit a berry in our genus. Fam. 18. Phytolaccaceae. 2: 25.

Fruit a utricle; stipules present (except in Scleranthus which has subulate, opposite connate leaves).

Fam. 19. Corrigiolaceae. 2: 26. Fruit an anthocarp, the persistent base of the corolla-like calyx enclosing a utricle.

Fam. 20. Nyctaginaceae. 2: 30. Fruit a capsule, dehiscent by valves, or teeth.

Capsule 2-several-celled; petals none. Fam. 21. Aizoaceae. 2:34.