Perennial herbs (sometimes flowering in the first year), prostrate to erect or scandent. Leaves and branches alternate or occasionally opposite, leaves entire. Flowers hermaphrodite or dioecious, sometimes polygamous, bibracteolate, in axillary and terminal sessile or pedunculate bracteate spikes or panicles, one flower in the axil of each bract. Perianth segments 5, oval- or lanceolate-oblong, membranous-margined with a thin to wider green centre, the perianth deciduous with the fruit but bracts and bracteoles persistent. Stamens 5, shortly monadelphous at the base, alternating with subulate or rarely narrowly oblong and truncate or emarginate pseudostaminodes. Ovary with a single pendulous ovule; style very short to slender and distinct; stigmas 2, short to long and filiform (sometimes solitary and capitate, flowers then probably functionally male). Utricle thin-walled, bursting irregularly. Seed compressed-reniform, firm, black.