137. Eleusine Gaertner, Fruct. Sem. Pl. 1: 7. 1788.
穇属 can shu
Authors: Shou-liang Chen & Sylvia M. Phillips
Annuals or tussocky perennials. Culms compressed. Leaf sheaths strongly keeled; leaf blades linear, usually folded; ligule membranous, usually with a ciliate fringe. Inflorescence of digitate or subdigitate spikelike racemes clustered at the top of the culm; racemes with closely imbricate, biseriate spikelets, terminating in a fertile spikelet. Spikelets laterally compressed, florets several, disarticulating between the florets (except the cultivated species E. coracana); glumes shorter than lemmas, persistent, 1–3(–7)-veined, keeled, awnless; lemmas membranous, 3-veined, glabrous, strongly keeled, keel thickened with 1–3 closely spaced additional veins, obtuse or acute. Grain ellipsoid to subglobose, trigonous in section, ornamented, pericarp free. x = 9. Fl. and fr. Jul–Sep.
Nine species: mostly in E and NE tropical Africa, one species a pantropical weed and one cultivated as a cereal; two species (one introduced) in China.
Eleusine, Acrachne, and Dactyloctenium form a group of closely related genera, remarkable for their unusual, ornamented grains enclosed within a free pericarp, which is easily removed when soaked in a drop of water.