25. Eragrostis unioloides (Retzius) Nees ex Steudel, Syn. Pl. Glumac. 1: 264. 1854.
牛虱草 niu shi cao
Poa unioloides Retzius, Observ. Bot. 5: 19. 1788; Eragro-stis amabilis (Linnaeus) Wight & Arnold ex Nees; E. formo-sana Hayata; P. amabilis Linnaeus.
Annual or perennial. Culms erect or geniculate at base, 20–60 cm tall, 2–3 mm in diam., 3–5-noded. Leaf sheaths glabrous and smooth, long pilose along the summit; ligules membranous, ca. 0.8 mm; leaf blades sublanceolate, flat, 2–20 × 0.3–0.6 cm, adaxial surface long pilose, abaxial surface smooth, apex acuminate. Panicle open, oblong, 5–20 × 3–5 cm; branch solitary, glabrous in axils. Spikelets purplish red at maturity, oblong, 5–10 × 2–4 mm, with pedicel 0.2–1 cm, 10–20-flowered; florets closely imbricate; rachilla persistent, lower glume 1.5–2 mm, upper glume 2–2.5 mm. Lemmas broadly ovate, veins prominent, apex acute, the lower lemma ca. 2 mm. Palea slightly shorter than the lemma, 2-keeled, very narrowly winged and ciliolate, falling off together with its lemma at maturity. Stamens 2; anthers purple, 0.2–0.5 mm. Caryopsis compressed, ellipsoidal, ca. 0.8 mm. Fl. and fr. Aug–Oct.
Mountain slopes, grasslands, roadsides. Fujian, Hainan, Jiangxi, Taiwan, Yunnan [W Africa, tropical Asia].