Monoecious or dioecious herbs or subshrubs, without stinging hairs and with linear cystoliths. Leaves 3-costate, petiolate, opposite, entire or dentate; stipules interpetiolar. Inflorescence axillary, of compact and globose or paniculate sessile or peduncled cymose clusters. Flowers minute, green unisexual, sessile; bracteate. Calyx (2-3-) 4-lobed or truncate and cupular in male flowers, lobes horned outside below the apex; unequally 3-lobed in female, median lobe largest, cucullate or gibbous. Stamens (2-3) 4; staminodes scale-like, inflexed in female flowers. Ovary straight, style absent, stigma penicillate; pistillode conical or oblong in male flowers. Achenes flattened, ovate or orbiculate, not or partly enveloped by calyx. Seeds with hardly any albumen.