Small diffuse, prostrate, annuals, glabrous-puberulous, vesiculate. Leaves alternate, ovate, petiolate, entire or lobed. Flowers minute, monoecious, unisexual, clustered, hidden among the leaves. Staminate flowers ebracteate, perianth hyaline, 5-lobed, stamens 1-4, filament long, stamens exserted. Pistillate flowers few in glomerules, usually 1-3, 2-3-bracteate, sessile, perianth absent, ovary ellipsoid, compressed; stigmas 2-capillary, styles very short, ovule sessile and erect. Seeds coriaceous, horse-shoe-shaped.