Lachnagrostis tenuis

Detailed description

Stiff, leafy tufts 180–360 mm tall, leaves narrow, more or less inrolled, panicles lax. Branching intravaginal. Leaf-sheath subcoriaceous, more or less obviously ribbed, glabrous, light brown. Ligule 1.0–3.2 mm, truncate, erose, minutely ciliate, undersides scabrid. Leaf-blade 20–120 × 0.3–0.9 mm, inrolled, undersides smooth, rarely scabrid near apex, upper surface ribbed and short-scabrid on ribs, margins smooth, apex obtuse. Culm 50–200 mm, usually included within uppermost leaf-sheath, internodes densely, finely scabrid below panicle. Panicle 30–120 × 20–120 mm, delicate, branches fine, scabrid, erect to spreading, bearing spikelets at tips. Spikelets 3–5 mm, light green to light brown. Glumes 1–3-nerved, elliptic-lanceolate, more or less acuminate, strongly keeled, keel finely scabrid in upper ½–⅔. Lemma 3.0–4.2 mm, more or less equivalent in length to glumes, firmly membranous, glabrous, papillose-scabrid, elliptic-lanceolate, lateral nerves sharply excurrent to c. 1 mm; central awn 3.5–6.5 mm, geniculate, emanating from lower one third of lemma. Palea 2.5–3.0 mm, c. ⅔ length of lemma, lanceolate, apex bifid, keels scabrid, margins submembranous, scabrid near apex. Callus hairs more or less dense, very short, 0.3–0.8 mm, about ¼ length of lemma. Rachilla prolongation 1.5–2.5 mm long, with very short hairs throughout except sometimes near tip, rarely completely glabrous. Lodicules 0.7–1.0 mm, lanceolate, acute. Anthers 0.5–0.9 mm. Seed 1.4–1.6 × 0.5–0.7 mm.