Perennial, dioecious herbs. Rhizome hard, short-creeping. Stems ± erect, subterete or terete, green or grey-green, unbranched. Leaves reduced to persistent sheathing bracts. Male and female inflorescences nearly similar. Male spikelets many-flowered, spikelets arranged in a branched inflorescence. Male flowers with 4–6, dark brown perianth parts. Female spikelets crowded, in dense clusters, individual spikelets indistinct. Female flowers with 5–6 dark brown perianth parts; staminodes 3 or absent; ovary unilocular; style with 3 branches. Fruit a small ovoid nut.
4 species in Australia, New Zealand, Chile, 2 endemic to Australia, 1 in Victoria.