10. Glyceria maxima (Hartman) Holmberg, Bot. Not. 1919: 97. 1919.
水甜茅 shui tian mao
Molinia maxima Hartman, Handb. Skand. Fl. 56. 1820; Glyceria aquatica (Linnaeus) Wahlberg (1820), not (Linnaeus) J. Presl & C. Presl (1819); G. spectabilis Mertens & Koch; Poa aquatica Linnaeus.
Perennial, rhizomatous; rhizomes long, thick. Culms stout, erect, 80–200 cm tall, up to 10 mm in diam. Leaf sheaths smooth or scabrid toward blade; leaf blades flat, light green, 25–50 cm × 8–16 mm, with transverse veinlets, abaxial surface scabrid, adaxial surface smooth or sparsely scabrid, apex acute; ligule 2–4 mm. Panicle ovate to oblong in outline, usually laxly contracted, 20–40 cm, exserted, spikelets many; branches 4–10 per node, obliquely ascending, relatively thick, scabrid. Spikelets narrowly oblong, 5–12 mm, florets 5–10, yellowish green or purple tinged; rachilla internodes smooth; glumes narrowly ovate, 1-veined, lower glume 2–3 mm, upper glume 3–4 mm, subacute; lemmas oblong, 3–4 mm, thinly herbaceous, 7-veined, veins scabrid, apex membranous, broadly obtuse; palea as long as lemma, keels wingless, scabrid. Stamens 3, anthers 1.2–1.8 mm. Fl. May–Jul. 2n = 28, 56, 60.
Marshy floodlands, stream and lake banks. Xinjiang [Kazakhstan, Russia (W Siberia westward); Europe; introduced in North America and Australia].
Glyceria aquatica (Linnaeus) J. Presl & C. Presl is a synonym of Catabrosa aquatica.