Trees, shrubs or rarely climbers, dioecious or monoecious. Exudate absent*. Unarmed*. Indumentum present, hairs simple or stellate. Stipules free*, simple, unlobed, entire *, not spine-like*, not leaf-like*, without glands. Leaves distributed evenly along stem, alternate, almost opposite or whorled, simple, unlobed, base symmetrical, margin toothed or almost entire, blade pellucid-punctate or not; blade sometimes glandular beneath at base; venation pinnate or with 3 strong veins from base; domatia absent*; stipel-like appendages sometimes present. Petiole present, without swellings or bends at base or apex*. Inflorescence with or without axis, axillary, terminal or cauline, spicate to paniculate, solitary or a few together, unisexual, the males many-flowered, the females lax, fewer-flowered; bracts glandular or not, not leaf-like*, green; pedicels present, sometimes very short, not articulated*, or flowers sessile. Male flowers: sepals 3–5; valvate, partially fused, greenish; petals 0; disc 0; stamens 6–8, free, partially fused or more or less completely fused; anther without conspicuous modification, thecae introrse in bud; pistillode present or 0. Female flowers: sepals 3–5, valvate, partially fused, rarely free, greenish; petals 0; disc 0; ovary locules 1–5, ovules per locule 1; styles 1–5, free or partially to completely fused (stigmas may be free), entire, very rarely2-branched at apex, styles or stigmas very long in neotropical species, not flat*, surface smooth*; staminodes absent. Fruit dehiscent, smooth, spiny, bristly or warty, greenish to brown; seed with outer layer sometimes fleshy, with or without a rudimentary caruncle; embryo flat, not minute, cotyledons leaf-like.
An asterisk * indicates a state has been assumed but not yet confirmed.
World Checklist: about 50 spp.
See: Secco, R. S. (2004) Alchorneae (Euphorbiaceae) (Alchornea, Aparisthmium, Conceveiba), Flora Neotropica Monograph 93. Organization for Flora Neotropica. New York Botanical Garden, Bronx, New York, U.S.A.