科名：禾本科 Gramineae

属名：早熟禾属 Poa

《中国植物志》第9(2)卷131页
  60．朗坦早熟禾（拟）
  Poa langtangensis Meld. in Hara et al. Enum. Flow. Pl. Nepal. 1:143. 1978.
  多年生，具细弱匍匐根状茎。秆疏丛生，高10-25厘米，纤细，直立。叶鞘平滑无毛；叶舌长0.5-1.2毫米；叶片扁平或对折，长2-5厘米，宽1-2毫米，脉细弱，平滑，分蘖叶狭窄，内卷。圆锥花序长3-5厘米，疏松开展；分枝孪生，长1-3厘米，纤细平滑，开展或反曲；小穗长3-3.5毫米，含2小花，带紫色；颖上部边缘膜质，脉不明显，第一颖长1.5-2毫米，具1脉，披针形，顶端尖，第二颖长2-2.5毫米，较宽，具3脉；外稃长圆形，先端尖，5脉不明显，脊和边脉下部具纤毛，脉间无毛，基盘有丰富绵毛，第一外稃长2.5-3毫米；内稃两脊上部微粗糙；花药紫色，长约1.5毫米。花期6月。
  产西藏。生于高山河谷草地，海拔4000米。分布于尼泊尔。模式标本采自尼泊尔中部。

《Flora of China》 Vol. 22 (2006)
Poa langtangensis  Melderis
朗坦早熟禾   lang tan zao shu he
Perennials, with isolated shoots, rhizomes present, slender. Culms isolated or few together, 9–25 cm tall, 0.6–0.8 mm in diam., erect, smooth, with 2 or 3 nodes above base, none or 1 exserted, and several short leaves at the base. Leaf sheaths smooth, glabrous, 3.5–5 cm, 1.5–2 × as long as blade, uppermost closed for just over 1/2 of length, lowermost soon withering, becoming fibrous, not persisting; blades flat or folded, thin, 1.5–5 cm × 1–1.5(–2) mm, surfaces and margins smooth, of tillers few, short; ligule 0.5–1 mm, abaxially smooth, glabrous, apex truncate to obtuse, smooth, collars smooth, glabrous. Panicle open, 3–5 × to 3 cm, longest internodes 1–2 cm; branches spreading, flexuous, (1 or)2 per node, capillary, smooth (hooks very rare), longest 1.5–2.5(–3) cm with 3–4 spikelets in distal 1/2. Spikelets narrowly lanceolate, green or purple tinged, 3–3.5 mm, 2–3 × longer than broad, florets 2; vivipary absent; rachilla smooth, glabrous; glumes green, narrow, keel weak, veins inconspicuous, surfaces smooth, very thinly papery, minutely punctate-papillate, lower glume 1.5–2.2 mm, 1(or 3)-veined, keel smooth or sparsely scabrid, upper glume 2–2.7 mm, broader (to 0.6 mm), 3-veined, keel minutely scabrid; lemmas oblong, slightly arched along the keel, very thinly papery, 2.5–3.3 mm, apex acute, with a narrow bronze band below the narrow whitish tip, keel and marginal veins proximally pilulose to short villous, intermediate veins faint, area between veins glabrous (not minutely bumpy), distally smooth to sparsely scabrid; callus webbed with hairs to 1/2 as long as lemma on the lowest floret; palea smooth, glabrous between keels, keels finely scabrid, 3–16 hooks per keel. Anthers ca. 1.5 mm. Fl. and fr. Jun–Jul.
Grassy places in alpine river valleys; ca. 4000 m. ?Xizang [Nepal].
Poa langtangensis could be a weak form of P. pagophila from a cold, shady habitat. Unlike P. calliopsis, it has narrow spikelets that are not so clustered and deflexed. Although we have not found a voucher specimen for the record from Xizang, the type, from Nepal, is from within 10 km of the Xizang border.