Perennials with short or long rhizomes. Culms erect, tufted, noded or nodeless. Leaves isobilateral, flattened to terete or reduced, glabrous. Inflorescence panicle-like, sometimes reduced; involucral bracts culm-like. Spikelets usually clustered, with 1–5 bisexual flowers; rachilla persistent. Glumes few, spirally arranged or obscurely distichous, keeled, usually the lowest 1–3 empty, often shorter than fertile glumes; perianth absent; stamens 3; style 3-fid, deciduous; style-base thickened, persistent on nut, fused as hemispherical to conical apex, often minutely hispid or papillose. Nut trigonous to terete, prominently to obscurely 3-ribbed, smooth at maturity, otherwise irregularly wrinkled.
About 30 species from tropical and temperate regions; 15 species in Australia, represented in all States. This genus has been at times included in Machaerina and both have been included in Cladium s. lat. (Blake 1969). Baumea teretifolia (R. Br.) Palla was reported for Victoria by Willis (1970, p. 244) on the basis of two collections from Beechworth. They are referable to B. planifolia.