水茅 shui mao

Arundo festucacea Willdenow, Enum. Pl. 1: 126. 1809; Donax borealis Trinius; Festuca borealis (Trinius) Mertens & Koch ex Rôhling; Fluminia arundinacea (Roemer & Schultes) Fries; F. festucacea (Willdenow) Hitchcock; Graphephorum arundinaceum (Roemer & Schultes) Ascherson; Schedonorus arundinaceus Roemer & Schultes (1817), not (Schreber) Dumortier (1824), nom. cons.

Plant with spreading spongy rhizomes. Culms robust, erect from a decumbent base, rooting at lower nodes, 0.7–2 m tall. Leaf sheaths smooth, glabrous; leaf blades 15–40 cm × 4–10 mm, smooth, margins sharply scabrid, apex finely acuminate; ligule 3–8 mm, truncate. Panicle loose, elliptic to ovate in outline, 15–30 cm; branches 2–4 at each node, erect at first, spreading after anthesis, naked in lower half, scabrid. Spikelets 7–10 mm, florets (2–)3–4(–5); glumes broadly lanceolate, lower glume 6.5–8 mm, upper glume 7.3–10 mm; lemmas 6–8 mm; palea lanceolate, ca. 6 mm. Anthers 2.5–3.4 mm. Fl. Jun–Aug. 2n = 28.

Shallow, slow-flowing water, swamps; below 1000 m. Heilongjiang, Jilin, Liaoning, Nei Mongol [Kazakhstan, Mongolia, Russia; SW Asia (Caucasus), NE Europe, North America].

This is a forage grass, providing hay from swampy areas.