孙必兴早熟禾 sun bi xing zao shu he

Type: China. Yunnan: Fugong Xian, above Bijiang ca. 9 km by road, W slope of Bilou Mts. (divide between Nu Jiang and Lancang Jiang drainages), 26°35'N, 98°59'E, opening in Abies-Tsuga forest-Fargesia thicket contact zone, 2900 m, 8 Sep 1997, R. J. Soreng, P. M. Peterson & Sun Hang 5222 (holotype, US; isotypes, KUN, PE, others to be distributed).

Haec species a P. eleanorae Bor foliorum superiorum vaginarum marginibus per dimididum longitudinis connatis, lemmate glabro atque glumis 1.5 mm brevioribus quam lemmatibus; a P. gammieana J. D. Hooker inflorescentiae ramis scabris, lemmatis paleaeque carinis glabris atque ligula plerumque breviore, 1–2(–5) mm; a P. dzongicola Noltie callo dorso lanuginoso atque ligula breviore differt.

Annuals or short-lived perennials. Major roots capillary to slender, 0.1–0.2 mm. Culms tufted, erect or slightly decumbent at base, 25–80 cm tall, 1–3.5 mm in diam., smooth or sparsely scabrid below nodes, nodes 2–4, 1 or 2 exserted, uppermost ca. 1/2 way up culm. Leaf sheaths smooth, glabrous, 6–15 cm, 0.5–1 × as long as blade, uppermost closed for ca. 1/2 of length; blades flat or folded, moderately thin, uppermost 8–30 cm × 1.5–5 mm, abaxial surface and margins smooth or sparsely scabrid, adaxially scabrid, keel and 4–10 primary veins abaxially pronounced, apex slender prow-tipped; ligule 1–2(–5) mm, apex obtuse, abaxially scabrid, collar glabrous. Panicle open, eventually exserted, 8–25 cm, longest internode ca. 4 cm; branches initially ascending and flexuous, eventually spreading or reflexed and lax, mostly 2 per node, scabrid all round, angled in part, longest 8–11 cm with 5–13 spikelets loosely arranged in distal 1/2. Spikelets lanceolate, purple tinged, (4–)5–7 mm, florets 2 or 3; vivipary absent; rachilla internodes ca. 1 mm, usually densely slender-scabrid to hispidulous; glumes thinner-textured than the lemmas, frequently purple on margins or all over, keel scabrid, surface uniformly minutely punctate, apex sharply acute, lower glume narrowly lanceolate, 3.3–4.6 mm, 1- or 3-veined, upper glume lanceolate 3.8–5 mm, 3-veined; lemmas 3.7–5.2 mm, moderately firm, apex sharply acute, margins very narrowly membranous, with a narrow purple band, keel and marginal veins scabrid, intermediate veins faint to moderately prominent, areas between veins usually densely scabrid over most of the surface; callus of proximal florets sparsely webbed, hairs short, callus of distal florets glabrous; palea scabrid throughout. Anthers 0.7–1.6 mm. Fl. and fr. Aug.

* Openings in upper forested and subalpine slopes, 2900–3900 m. NW Yunnan.

Poa sunbisinii differs from P. eleanorae by having more closed leaf sheaths, a lack of hairs on the lemma keels, and shorter spikelets with glumes shorter than the lemmas by (on average) ca. 1.5 mm. It has a long palea as in P. gammieana, but that species has smooth inflorescence branches, pilose lemma and palea keels, and longer ligules. Poa dzongicola has glabrous calluses and longer ligules.