Description from Flora of China
Costia Willkomm (1858), nom. illeg. superfl., not Willkomm (1860).
Plants perennial, with creeping rhizomes or culms tufted. Culms erect or geniculate at base. Sheaths of vegetative shoots often closed almost throughout their length, usually with lanceolate auricles; leaf blade flat or involute. Spike linear-oblong or ovoid; rachis tough, pubescent. Spikelets 1 per node, divergently or pectinately arranged, sessile, laterally compressed, with 3–10 florets; rachilla disarticulating above glumes and between florets. Glumes linear to narrowly ovate, hardened, 1–5-veined, 1-keeled to base, tapering to an acuminate or shortly awned tip in which veins converge. Lemma lanceolate-oblong, leathery, 5–7-veined, glabrous or pilose, apex acute or with straight awn; midvein slightly keeled; callus very short. Palea ± equaling lemma, pilose along keels, rarely smooth and glabrous, apex usually 2-toothed. Lodicules ciliate at margin. Caryopsis somewhat adherent to lemma and palea. x = 7.
The authors have seen no specimens of Agropyron kanashiroi Ohwi (J. Jap. Bot. 19: 167. 1943; Elytrigia kanashiroi (Ohwi) Melderis; Pseudo-roegneria strigosa (M. Bieberstein) A. Löve subsp. kanashiroi (Ohwi) A. Löve; Roegneria kanashiroi (Ohwi) K. L. Chang), described from "Mongholia interior" and also recorded from Ningxia (in Fl. Ningxia. 2: 359. 1988).
About 15 species: mainly in Asia and Europe; introduced and widely cultivated in North America; five species (one endemic) in China.