Dioecious trees or shrubs. Leaves 3-costate or pinnately veined, petiolate alternate entire or crenulate; stipules intrapetiolar, bifid. Inflorescence of solitary or laxely cymose capitate, dense flowered heads. Flowers uni sexual, small. Calyx 4-lobed, lobes ovate, acute in male flowers; tubular, ventricose minutely 4-toothed and adnate to ovary in female flowers. Stamens as many as calyx lobes; staminodes absent. Ovary erect, style absent, stigma penicillate; pistillode obovate-clavete. Achenes adnate to and completely enclosed by slightly fleshy fruiting calyx.