Annual, monoecious or dioecious, herbs; stems erect or prostrate, simple to highly branched, glabrous to pubescent. Leaves alternate, petiolate; blade ovate, elliptical or rhombic, apex usually obtuse or truncate and apiculate, base cuneate and decurrent on petiole; primary and secondary venation often lighter coloured and prominent on upper surface. Inflorescences essentially cymose, glomerules aggregated into axillary clusters, and often also aggregated into terminal spikes, thyrses or panicles; bracts and bracteoles present. Flowers unisexual; tepals 3-5, scarious, apiculate, often persistent; stamens (2)3-5, filaments free, slender, anthers 4-locular; ovary at top rounded or thickened, stigmas 2-3. Fruit a dry, circumscissile or apparently indehiscent utricle; seed lenticular or ovoid, erect, exarillate.