黄穗白茅 huang sui bai mao

Perennial, basal sheaths becoming fibrous; rhizomes spreading, internodes very short. Culms solitary or tufted, 70–125 cm tall, 3–7 mm in diam., 3- or more-noded, nodes glabrous. Leaf sheaths longer than internodes, crowded below, glabrous except for silky hairs at mouth; leaf blades flat, 20–60 × 0.5–1 cm, culm blades 1–7 cm, glabrous or adaxial surface puberulous, margins smooth, base narrowed to midrib, apex long acuminate; ligule 0.5–1 mm. Panicle cylindrical, silky hairy, 12–17 cm, branches short, erect or ascending, discrete below. Spikelets 3–4 mm; callus hairs ca. 4 mm, equal to spikelet; glumes 4–5(–7)-veined, back pilose in lower 1/3 with silky hairs about as long as spikelet, upper margins ciliate, apex obtuse or erose; lower lemma broadly oblong, ca. 1/2 length of glumes, ciliate, irregularly denticulate; upper lemma oblong, 1/3 length of glumes, 2–3-denticulate, ciliate, palea similar to lemma. Anthers 2, 2.5–2.8 mm. Stigmas yellowish brown. Fl. and fr. summer to autumn.

* Mixed forests, along rivers, valleys. Hainan.

This species, which appears to be confined to Hainan, can be readily distinguished from the more common Imperata cylindrica by its much shorter spikelet hairs and yellow-brown (vs. purple-black) stigmas.