Monoecious, perennial herbs. Leaves alternate (in Australian species), membranous, 3-veined from near base; petiolate, stipulate. Inflorescences axillary, unisexual, few-flowered, without involucre. Male inflorescences 2–4-flowered, pedunculate; flowers sessile at peduncle apex; perianth 2-lipped, the larger lobe incurved; stamen 1; pistillode absent. Female inflorescences 2–5-flowered, sessile, usually in the leaf axils below those subtending male inflorescences; flowers subsessile; perianth present, tubular, with 2 or 3 gradually narrowed teeth; stigma thread-like. Achene compressed, ellipsoid, enclosed within persistent perianth.
2 species, 1 occurring in Australia and New Zealand, the other in Ethiopia and Kenya.