细杆早熟禾 xi gan zao shu he

Perennials, densely tufted; shoots extra- and intravaginal. Culms ascending to erect, 19–40 cm tall, ca. 1 mm in diam., smooth, nodes 2–4, none or 1 exserted, uppermost node to 1/3–1/2 way up culm. Leaf sheaths weakly keeled, smooth, 5–8 cm, 2–4 × as long as blade, uppermost closed for 2/5–3/5 of length; blade flat or folded, thin, 1.5–8 cm × 2–2.8 mm, apex prow-tipped, abaxially smooth, often ribbed, adaxially finely scabrid, margins smooth or scabrid, of tillers 1–3.5 cm; ligule 1–3 mm, abaxially smooth, apex obtuse to acute, of tiller and lower leaves 0.2–0.5 mm, abaxially scabrid, collar smooth. Panicle loosely contracted, 5–8 cm, longest internodes 1.5–2 cm; branches ascending, 1 or 2 per node, proximally rounded, smooth, distally scabrid angled, longest 2.5–4 cm with 6–12 spikelets in distal 1/2. Spikelets lanceolate, slightly purple tinged, 4–6.5 mm, florets 2–4; vivipary absent; rachilla internodes to 1 mm, pilulose to short villous or sparsely scabrid; glumes papery, strongly keeled, keel apically sparsely scabrid, sides punctate-papillate, somewhat glaucous, apex sharply acute to acuminate, lower glume 3–4.1 mm, 1(–3)-veined, upper glume 4–4.7 mm, prominently 3-veined, lateral veins to 2/3 as long; lemmas 3.5–4.7 mm, apex acute to acuminate, margins purple, keel villous for 3/4 of length, marginal veins for 2/3, and sometimes intermediate veins to 1/2 length, areas between veins proximally densely pilulose to shortly villous, distally minutely bumpy; callus densely webbed; palea densely pilulose to villous between keels, keels scabrid, medially densely pilulose to villous. Anthers (1–)1.2–1.5 mm. Fl. and fr. Jun–Aug.

* Alpine grassy slopes. Taiwan.

Poa tenuicula differs from P. nankoensis in being taller and having panicles longer, spikelets pubescent between lemma veins and on rachilla, and anthers longer.