XXX. EUPHORBIACEÆ.
Trees, shrubs, or herbs, with acrid juice, and alternate stipular leaves. Flowers monœcious or diœcious; calyx 3—6-lobed or parted, the divisions imbricated in the bud, or wanting; corolla 0; stamens 2 or 3, or as many or twice as many as the calyx-lobes; anthers 2-celled, opening longitudinally; ovules 1 or 2 in each cell, suspended, anatropous; raphe ventral; micropyle superior. Fruit a drupe or capsule. Seeds albuminous; cotyledons flat, much longer than the superior radicle.
The Euphorbia family, widely distributed over tropical and temperate regions, with some one hundred and thirty genera and over three thousand species, is represented in the United States by three arborescent genera, with only five species, and by many shrubby herbaceous and annual plants.
CONSPECTUS OF THE ARBORESCENT GENERA OF THE UNITED STATES.
Fruit drupaceous. Nutlets usually 1-celled and 1-seeded; stamens as many or twice as many as the calyx-lobes, free.1. [Drypetes.] Nutlets 6—8-celled and 6—8-seeded; stamens 2 or 3, united into a column.2. [Hippomane.] Fruit a 3-lobed capsule splitting into three 2-valved 1-seeded carpels.