Slender densely tufted perennials; culms erect or pendulous, unbranched. Leaves mainly basal; leaf-blades narrow, usually filiform; ligule a narrow ciliate membrane. Inflorescence a solitary terminal subsecund spike, the spikelets biseriate, overlapping and more or less appressed to the rhachis. Spikelets 2-many-flowered, linear to elliptic, laterally compressed, disarticulating between the florets; glumes 1-nerved or rarely the upper 3-nerved, narrow, keeled, persistent, membranous, unequal, shorter than the lemmas or the upper glume exceeding the lower lemmas, lower glume often asymmetrical; lemmas 3-nerved, rounded or obtusely keeled, membranous, glabrous, the tip 2-toothed or subentire, sometimes with additional lobes between the teeth, mucronate or 1-3-awned; palea usually winged and ciliolate along the margins; callus villous and sometimes bearded in front. Caryopsis narrow, trigonous to almost terete in cross-section.