Description from Flora of China
Rottboellia repens G. Forster, Fl. Ins. Austr. 9. 1786; Mon-erma repens (G. Forster) P. Beauvois.
Perennial, stoloniferous, often very widely spreading. Culms tough, 20–50 cm tall, much branched. Leaf sheaths usually keeled, glabrous; leaf blades stiff, flat or involute, glaucous, 3–20 cm, 2.5–5 mm wide, glabrous or adaxially pilose near ligule, margins scabrous, apex acuminate; ligule 0.3–0.8 mm. Raceme erect, 5–15 cm; spikelets sometimes paired on each internode toward raceme base; rachis scabrous-hispidulous, internodes 3–5 mm. Spikelets 10–12 mm, florets often 2; lower glume membranous, triangular, up to 0.8 mm or absent; upper glume narrowly lanceolate, as long as spikelet, leathery, scabrous, apex caudate-aristate; lower lemma broadly lanceolate, 3.7–4.5 mm, puberulous near base, cartilaginous in lower two-thirds, thinner and scabrous above, apex acute. Anthers 1.5–2 mm. Caryopsis strongly dorsally compressed, plano-convex, 1.6–2 mm. 2n = 54.
Rocky and sandy seashores, especially coral sand. Taiwan [Japan (Ryukyu Islands), Indonesia, Malaysia, New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; E Africa, N Australia, Indian Ocean Islands, Pacific Islands (Polynesia)].