阿尔泰旱禾 a er tai han he

Annual. Culms 5–45 cm tall, solitary or tufted, slender. Leaf blade 2–10 cm × 1–4 mm, flat or folded, abaxial surface scabrid or smooth, adaxial surface scabrid, apex acuminate; ligule 1–3 mm. Panicle delicate, narrowly to broadly ovate in outline, 2–20 cm; branches 3–10 per node, subcapillary, scabrid. Spikelets elliptic, 4–6.5 mm, florets 2–6, green or purple tinged; lower glume lanceolate, 1–2 mm, apex acute, up to 1/2 as long as lowest lemma; upper glume narrowly ovate, 1.5–2.5 mm, apex acute or subacute; lemmas 2–4 mm, glabrous or scantily hairy to densely appressed-pubescent along lower part of veins, margins narrowly membranous, apex acuminate or often with a mucro to 0.5 mm; palea a little shorter than lemma. Anthers 0.4–1 mm. Fl. and fr. May–Aug. 2n = 28, 42.

Borders of streams and drying ponds, dry stony or sandy places; 1300–4000 m. Xinjiang, Xizang [Afghanistan, NW India, Kashmir, Kazakhstan, Kyrgyzstan, Pakistan, Russia, Tajikistan, Turkmenistan, Uzbekistan; SW Asia].

Poa diaphora is a widespread and variable species and is sometimes divided into infraspecific taxa. The most distinct is subsp. oxy-glu-mis, with hairy lemma veins appearing as silky-white stripes, although intermediates do occur. Small plants (up to 15 cm) with relatively long lemmas (over 3.5 mm) are sometimes distinguished, as subsp. diaphora, from the bulk of the species, which would then be placed in a "subsp. songarica," but this distinction is much less clear-cut and is not followed here.