Plants dioec. Male and female infls often dissimilar. Spikelets us. many-fld in both sexes; upper floral bracts imbricate; bractlets 0, or rarely 2 in ♀ (0 in N.Z. sp.). Tepals 6–(4), variously shaped. ♂ with 3–(2) stamens; anthers 1-celled; ovary rud., or 0. ♀ with 3 or 0 staminodia; ovary 1-locular, with a single, pend. ovule; styles 3–(2),free or united to midway. Fr. ind., or occ. dehiscing along one side. Rush-like, perennial herbs. Culms ∞, terete, simple (in N.Z. sp.), from a stout, creeping rhizome. Lvs reduced to persistent sheaths, closely appressed to culms. About 15 spp., mainly endemic to Australia, but 1 in Southeast Asia and 1 in Southern Chile. The N.Z. sp. is endemic.