1. Polypogon viridis (Gouan) Breistroffer, Bull. Soc. Bot. France. 110(89 Sess. Extraord.): 56. 1966.
苔绿棒头草 tai lü bang tou cao
Agrostis viridis Gouan, Hortus Regius Monspeliensis: 546. 1762; Agrostis semiverticillata (Forsskål) C. Christensen; Phalaris verticillata Forsskål; Polypogon semiverticillatus (Forsskål) Hylander.
Perennial, stoloniferous; stolons slender, spreading, rooting at nodes. Culms geniculately ascending, 20–100 cm tall. Leaf blades linear, flat, 3–12 cm, 2–8 mm wide, scaberulous on both surfaces, apex acute; ligule 2–5 mm. Panicle contracted, lanceolate to oblong, lobed and often interrupted, 5–15 cm; branches semiverticillate, ascending, bearing densely clustered spikelets. Spikelets narrowly oblong, 1.5–2.5 mm; glumes narrowly elliptic-oblong, scabrid, lightly keeled upward, apex obtuse, awnless; lemma broadly elliptic, ca. 1 mm, awnless, apex truncate, minutely denticulate; palea almost as long as lemma. Stamens 3, anthers 0.4–0.7 mm. Caryopsis oblong, ca. 1 mm.
Aquatic grass rooting in sand and mud of streams, marshy grasslands; ca. 2600 m. Yunnan [Kazakhstan, Kyrgyzstan, Pakistan, Tajikistan, Turkmenistan, Uzbekistan; N Africa, SW Asia, S Europe, NW India; introduced in S Africa, America, Australia].