Creeping perennial herbs, rooting at nodes or erect small shrubs (not in Australia). Leaves simple, exstipulate. Inflorescence axillary, a simple umbel, or 2–3 times compound; bracts few or absent. Flowers bisexual, lateral ones sometimes male; sepals forming a minutely lobed persistent ring, or absent; petals broad, obtuse; nectary flat. Fruit laterally compressed; mericarps convex, prominently 3–5-ribbed with reticulate connections; carpophore undivided, persistent.
About 40 species, mainly in the Southern Hemisphere with 1 widely distributed species extending to Australia.