无芒鸭嘴草 wu mang ya zui cao

Perennial, strongly rhizomatous; rhizomes clothed in cataphylls. Culms often red, much branched, stoloniferous or scrambling, several meters long, flowering culms erect, up to 60 cm, nodes glabrous. Leaf sheaths ciliate along outer margin, otherwise glabrous or sparingly appressed hairy; leaf blades lanceolate, tinged reddish brown, 2–10(–18) × 0.3–1.7 cm, glabrous or abaxial surface sparingly pilose, margins smooth or scaberulous, base cordate, very shortly pseudopetiolate, apex acute; ligule 0.2–0.6 mm. Racemes usually paired, appressed back to back, 2–5 cm, base enclosed by subtending sheath; rachis internodes and pedicels oblong, triquetrous, outer angle narrowly winged, inner angles glabrous or ciliolate. Sessile spikelet lanceolate, 4.8–7 × 2.5–2.8 mm; lower glume leathery with expanded rounded flanks in lower 2/3, herbaceous, strongly veined and sharply 2-keeled below apex, glabrous, winged from near base, apex entire; upper glume winged on upper keel; upper lemma subentire, mucronate or with ca. 1 mm awnlet. Pedicelled spikelet laterally compressed, otherwise resembling sessile or smaller, awnless.

Sands near the sea; below 100 m. Taiwan [Cambodia, India, Indonesia, Japan (S Ryukyu Islands), Malaysia, Myanmar, New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; Australia (Queensland)].

This seashore plant forms extensive colonies that bind the sand at the back of sandy beaches.