大穗鸭嘴草 da sui ya zui cao

Ischaemum laeve Ridley.

Perennial. Culms erect, 1–2 m tall, sparingly branched in upper part, nodes glabrous. Leaf sheaths longer than internodes, pilose with tubercle-based hairs, especially along margins and toward blade; leaf blades broadly linear, 5–33 × 0.5–1.8 cm, abaxial surface densely to sparsely appressed pubescent, adaxial surface glabrous, margins scabrid, base narrowed, apex acuminate; ligule 3–5 mm. Racemes terminal, paired, appressed back to back, 6–12 cm; rachis internodes columnar, slightly expanded upward, triquetrous, ciliate along outer angle, sometimes only at base, inner angles glabrous. Sessile spikelet oblong-lanceolate, 6.5–8 × 1.7–2 mm; lower glume 2-keeled throughout, leathery except near apex, usually with 2–4 marginal tubercles in lower half, sometimes almost smoooth, or tubercles transversely connected into coarse shallow ridges, herbaceous above with anastomosing green veins, keels narrowly winged; upper lemma entire, awnless or mucronate, or 2-lobed and awned; awn up to 1 cm, weakly geniculate. Pedicelled spikelet dorsally compressed, equaling or slightly longer than sessile, strongly asymmetrical, winged on one keel only, wing 0.3–1.5 mm wide, awnless; pedicel very short, stout.

Moist meadows, field margins; 800–1000 m. W Yunnan [Malaysia, Myanmar].