Short, caespitose annuals or biennials. Leaf-sheath open. Ligule membranous. Leaf-blade flat to rolled, narrow. Culm glabrous. Inflorescence a single, simple spike, breaking up at maturity by disarticulation of rachis below each spikelet. Spikelets 1-flowered, sessile, solitary and alternating on opposite sides of rachis, broadside to rachis and ± sunk in cavities within it, falling away with rachis internodes at maturity. Glumes 2, adjacent, strongly nerved, coriaceous, ≥ lemma, tip acute. Lemma 3-5-nerved, membranous, at right angles to rachis. Palea ≤ lemma, hyaline, keels 2, rather indistinct. Lodicules 2, glabrous. Stamens 3. Ovary glabrous; styles free to base. Caryopsis longitudinally grooved; embryo small; hilum punctiform or shortly elliptic. Fig. 7.