6. Microstegium petiolare (Trinius) Bor, Indian Forest Rec., Bot. 1(3): 87. 1938.
柄莠竹 bing you zhu
Spodiopogon petiolaris Trinius, Mém. Acad. Imp. Sci. St.-Pétersbourg, Sér. 6, Sci. Math. 2: 301. 1833; Andropogon petiolaris (Trinius) Steudel; Ischaemum petiolare (Trinius) Hackel; Microstegium yunnanense R. J. Yang.
Perennial, clump-forming or rambling. Culms hard, up to 2 m long, farinose below nodes, nodes densely bearded in tuft at sheath margin or all round. Leaf sheaths glabrous or tuberculate-pilose, margins broad at apex, extended into ligule; leaf blades lanceolate, 15–20 × 1–1.5 cm (excluding pseudopetiole), adaxial surface glabrous, adaxial surface pilose, midvein white, margins scabrid, base narrowed to a pseudopetiole up to 4 cm in lower blades, apex setaceous; ligule 4–11 mm. Racemes 6–20, corymbiform on 2–5 cm axis, lower racemes sometimes on side branches, straw-colored tinged purplish, 6–10 cm; rachis internodes linear, shortly ciliate, equaling spikelet. Sessile spikelet 4.7–5 mm; callus hairs short, soft; lower glume oblong, back grooved, granular-scabrid, 6–8-veined, sharply keeled, keels slightly winged near apex, apex obtuse-denticulate; upper glume sharply keeled, granular-scabrid, apiculate; lower floret staminate, lemma narrowly oblong, subequaling glumes, palea well developed; upper lemma ovate-oblong, 3–4 mm, 2-lobed to about middle; awn geniculate, 0.8–1 cm. Anthers 3, ca. 3 mm. Fl. and fr. Aug–Oct.
Grassy places along roadsides, sometimes scrambling through shrubs; ca. 2100 m. Yunnan [NE India, Myanmar, Nepal].
This is a distinctive species used for forage. The hard, rambling culms, broad, pseudopetiole leaf blades with long ligules, and corymbose inflorescence of many racemes all contribute to a recognizable habit.