51. Poa stapfiana Bor, Kew Bull. . 1949: 239. 1949.
斯塔夫早熟禾 si ta fu zao shu he
Poa tremula Stapf in J. D. Hooker, Fl. Brit. India 7: 344. 1896 ["1897"], not Lamarck (1791); P. tremula var. micran-thera Stapf.
Perennials, loosely tufted, weakly stoloniferous; shoots extra- and intravaginal. Culms 20–60 cm tall, 0.6–1.4 mm in diam., erect or obliquely ascending, smooth, glabrous, nodes 2 or 3, 1 or 2 exserted. Leaf sheaths loose, smooth, glabrous, 5–10 cm, slightly shorter than blade, uppermost closed for 1/4–1/3 of length; blade flat or folded, thin, 5–14 cm × 1–5 mm, adaxially sometimes scabrid, margins scabrid, apex slender prow-tipped or mucronate; ligule 2.5–5 mm, abaxially smooth, apex obtuse. Panicle open, lax, 8–25 cm, longest internodes 2.2–4 cm; branches widely spreading, flexuous, 2 per node, slender, proximally smooth, distally scabrid angled, longest 3.5–7 cm with 9–20 spikelets in distal 1/2. Spikelets elliptic to oblong, green or grayish, 4–6 mm, florets 3–6; vivipary absent; rachilla smooth, glabrous or pilulose; glumes subequal or lower to 1.5 mm shorter, scabrid only on keel, apex acuminate, faintly or not evidently punctate-papillate, lower glume lanceolate to elliptic, 2.7–3.9 mm, 1(or 3)-veined, upper glume oblong, 3–4.5 mm, faintly 3-veined; lemmas oblong, very thinly papery, 3–4.5 mm, apex acute, keel villous for 3/4 of length, marginal veins to 1/2, intermediate veins prominent, areas between softly pilulose; callus webbed; paleas shorter than the lemma, keels scabrid, medially pilulose. Anthers 0.7–1.2 mm. Fl. and fr. Jul–Sep.
Alpine meadows; 2500–4300 m. ?Xizang [N India, Kashmir, Nepal, Pakistan; SW Asia (Iran)].
This species approaches Poa himalayana on one end of its range of variation and P. hirtiglumis on the other, but it has longer lemmas and generally longer anthers than either of those species. The occurrence of this species in China requires confirmation.