30. Deyeuxia debilis (J. D. Hooker) Veldkamp, Gard. Bull. Singapore. 37: 220. 1985 [“1984”].
细弱野青茅 xi ruo ye qing mao
Calamagrostis debilis J. D. Hooker, Fl. Brit. India 7: 262. 1896 ["1897"]; Agrostis debilis (J. D. Hooker) Bor (1960), not Poiret (1810); A. neodebilis Bennet & Raizada.
Perennial, rhizomatous; rhizome very slender.Culms loosely tufted, very slender, ascending, 15–45 cm, ca. 1 mm in diam., 2–3-noded, sparsely leafy. Leaf sheaths scaberulous near blade, otherwise smooth; leaf blades narrowly linear, thin, 2–5 cm, 1.5–2 mm wide, smooth, apex acute; ligule 1.5–2 mm, truncate-lacerate. Panicle narrow, loosely contracted, 2.5–12.5 × 1–2 cm; branches in whorls of 2–5, narrowly ascending to suberect, up to 3 cm, smooth; pedicels capillary. Spikelets 3–4 mm, light brownish purple to grayish; glumes subequal, lanceolate, 1-veined, smooth on keel, apex acuminate; callus hairs equal to or exceeding lemma; lemma 2.2–2.8 mm, hyaline, smooth, apex minutely toothed; awn arising from upper 1/4–1/3 of lemma back, weakly geniculate, 4.5–5 mm; palea slightly shorter than lemma; rachilla extension absent. Anthers ca. 0.5 mm.
Alpine meadows; 3300–3400 m. Xizang [India (Sikkim)].
This is a very seldom collected species with a delicate habit and exceptionally small anthers. Its generic position is anomalous, as it lies on the boundaries with both Agrostis (small spikelets, no rachilla extension) and Calamagrostis (long callus hairs, hyaline lemma). It is retained here in Deyeuxia because of its relatively long floret in relation to the glumes and its general similarity to other slender montane species of Deyeuxia.