Slender annuals or more rarely perennials with erect nodeless culms, tufted or on slender rhizomes, with leaves basal and often reduced to sheaths; or elongate aquatic perennials with slender culms rooting at the nodes, sometimes floating. Involucral bracts 0–2, exceeding inflorescence, usually lowest erect and leaf-like, often falling early. Inflorescence a pseudolateral sessile head of one to several (occasionally numerous) spikelets with numerous flowers; glumes spirally arranged or rarely distichously arranged, mostly folded laterally when immature but spreading almost flat at maturity; hypogynous bristles absent; stamens 1–3; style 2- or 3-fid, not enlarged at base, deciduous. Nut trigonous or lenticular or rarely subglobose, smooth or trabeculate or minutely verrucose or pitted but not rugose.
A genus of 69 species world-wide, widespread, especially Africa and Australia; 24 species in Australia (Muasya & Simpson 2002), represented in all States.
Muasya, A.M. & Simpson, D.A. (2002). A monograph of the genus Isolepis R.Br. (Cyperaceae), Kew Bulletin 57: 257-362.