牛筋草 niu jin cao

Cynosurus indicus Linnaeus, Sp. Pl. 1: 72. 1753.

Annual. Culms tufted, erect or geniculate at base, 10–90 cm tall. Leaf sheaths glabrous or tuberculate-pilose; leaf blades flat or folded, 10–15 × 0.3–0.5 cm, glabrous or adaxial surface tuberculate-pilose; ligule ca. 1 mm, membranous, at most sparsely ciliolate. Inflorescence digitate, racemes (1–)2–7, linear, ascending, 3–10 × 0.3–0.5 cm, one raceme often set below the rest. Spikelets elliptic, 4–7 mm, florets 3–9; glumes lanceolate, scabrid along keel; lower glume 1-veined, 1.5–2 mm; upper glume with small additional veins in the thickened keel, 2–3 mm; lemmas ovate, 2–4 mm, keel with small additional veins, acute; palea keels winged. Grain blackish, oblong or ovate, obliquely striate with fine close lines running vertically between the striae. Fl. and fr. Jun–Oct. 2n = 18.

Disturbed places, roadsides. Anhui, Beijing, Fujian, Guangdong, Guizhou, Hainan, Heilongjiang, Henan, Hubei, Hunan, Jiangxi, Shaanxi, Shandong, Shanghai, Sichuan, Taiwan, Tianjin, Xizang, Yunnan, Zhejiang [tropics and subtropics].

This pantropical, annual weed is a forage grass and is used for Chinese medicine.