Herbs , annual, caulescent, taprooted; sap not milky. Leaves alternate; stipules caducous, free. Leaf blade broadly ovate, margins toothed; venation nearly palmate. Inflorescences axillary, capitate cymes, short-pedunculate, bracteate. Flowers: staminate and pistillate on same plants. Staminate flowers: calyx 4-lobed; stamens 4, inflexed. Pistillate flowers: calyx green, 4-lobed, pubescent; ovary superior, oblique, 1-locular; style unbranched, nearly lateral. Syncarps globose; each achene surrounded by its enlarged, persistent calyx.