XXXI. ANACARDIACEÆ.
Trees or shrubs, with terete pithy branchlets, resinous juice, and alternate simple or pinnate leaves, without stipules, and scaly or naked buds. Flowers regular, minute, diœcious, polygamo-diœcious, or polygamo-monœcious; calyx-lobes and petals 5, imbricated in the bud or 0; stamens as many as the petals and alternate and inserted with them on the margin or under an hypogynous annular fleshy slightly 5-lobed disk; filaments filiform; anthers oblong, introrse, 2-celled, the cells opening longitudinally; ovary 1-celled; styles 1—3; ovule solitary, suspended from the apex of a slender funicle rising from the base of the cell, anatropous; micropyle superior; styles 3, united or spreading; stigmas terminal. Fruit drupaceous. Seed without albumen; seed-coat thin and membranaceous; embryo filling the cavity of the seed; cotyledons flat, accumbent on the short radicle.
The Sumach family with some sixty genera is mostly confined to the warmer parts of the earth’s surface and contains the Mango, Pistacia, and other important trees. In the flora of the United States four genera have arborescent representatives.
CONSPECTUS OF THE ARBORESCENT GENERA OF THE UNITED STATES.
Flowers without petals, and in the species of the United States, without a calyx.1. [Pistacia.] Flowers with a calyx and petals. Flowers usually diœcious by abortion; styles lateral, spreading; pedicels of the abortive flowers becoming long and plumose at maturity; fruit compressed, very oblique; leaves simple, deciduous.2. [Cotinus.] Flowers mostly diœcious; styles terminal, short, united; stigma 3-lobed; fruit ovoid, glabrous; leaves unequally pinnate, persistent.3. [Metopium.] Flowers polygamo-diœcious or polygamo-monœcious; styles terminal, spreading; fruit usually globose, naked or clothed with acrid hairs; leaves unequally pinnate, trifoliolate or rarely simple, deciduous or rarely persistent.4. [Rhus.]