Glyceria ussuriensis Komarov.

Perennial, rhizomatous; rhizomes long, thick. Culms robust, hard, 80–110 cm tall, 5–8 mm in diam. Leaf sheaths not prominently keeled, lower sheaths scabrid, with transverse veinlets; leaf blades flat or margins inrolled, firm, up to 40 cm × 5–12 mm, abaxial surface smooth, adaxial surface scabrid, transverse veinlets present, apex abruptly acute; ligule 0.3–1 mm. Panicle ovate in outline, 15–25 cm, exserted, spikelets many; branches 2 or 3 per node, ascending, scabrid. Spikelets elliptic to ovate-oblong, 6–8 mm, florets 4–7, pale green, yellowish brown at maturity; glumes ovate-oblong, membranous, 1-veined, lower glume 1.5–2 mm, upper glume 1.8–2.5 mm, apex obtuse; lemmas lanceolate-oblong, thinly herbaceous, 3–3.5 mm, minutely granular, 7-veined, veins finely scabrid, margins and apex membranous, apex subacute; palea as long as or slightly longer than lemma, keels wingless, scaberulous, apex emarginate. Stamens 2, anthers 0.6–0.8 mm. Fl. and fr. Jul–Sep. 2n = 20.

Species nos. 6–10 belong to Glyceria sect. Hydropoa Dumortier, characterized by a strongly rhizomatous habit, rounded leaf sheaths, large panicle with many spikelets, short, laterally compressed spikelets, and wingless palea keels.

Glyceria formosensis Ohwi (Acta Phytotax. Geobot. 2: 164. 1933) was placed in synonymy under G. leptolepis in Taiwanese literature, but it is excluded from that species by its soft habit, scabrid panicle branches, and especially by the presence of 3 stamens. While clearly a member of G. sect. Hydropoa, it has not been possible to assign it to another species. It is apparently known only from the type gathering.

Swampy forests, watersides of streams, lakes, ditches. Anhui, Gansu, Heilongjiang, Henan, Hubei, Jiangxi, Nei Mongol, Shaanxi, Shandong, Taiwan, Zhejiang [Japan, Korea, Russia (Ussuri)].