Lachnagrostis ammobia

Detailed description

Mounding to trailing, somewhat lax glaucous to reddish-green, perennial, tufted grass forming patches up to 1 m diameter and 0.35 m tall; leaves markedly involute, panicles rather lax, disarticulating readily. Branching extravaginal. New shoots with 1-2 blunt-tipped sheaths at base and with the lowest leaf-blade often much reduced. Leaf-sheath submembranous, distinctly ribbed, smooth, rarely scabrid above. Ligule 1.5–4.5 mm, tapering above to an acute apex or denticulate, undersides scabrid. Leaf-blade 60–160 × 0.4–0.8 mm, involute, to 1.2 mm wide if flat, undersides smooth to scabrid (particularly near and at apex), upper surface finely scabrid; margins fine scabrid, apex fine subacute to obtuse. Culm 100–150 mm long, slender, usually included within uppermost leaf-sheath, internodes glabrous. Panicle 70–160 × 15–150 mm; branches few, these long, filiform, more or less closely and finely scabrid, each tipped by a single spikelet. Spikelets 4.5–7.0 mm, light green to purple-green. Glumes more or less equal, narrowly elliptic-lanceolate, scabrid above and on mid-nerve and hyaline margins or sometimes sparsely scabrid throughout. Lemma 2.8–3.7 mm long, more or less ½ length of glumes, 5-nerved, densely covered throughout by long silky hairs, oblong, truncate, lateral nerves minutely excurrent, rarely lemma less hairy near apex and scabrid nerves clearly visible; awn 4.0–6.0 mm, very fine, straight, or more or less curved, more or less mid-dorsal. Palea ⅔–¾ length of lemma, keels 0.1 mm part, apex bifid. Callus hairs dense, 1.5–2.0 mm, to ⅔ length of lemma. Rachilla prolongation 0.5–0.8 mm long, tipped by a dense tuft of hairs 1–2 mm long. Lodicules 0.9–1.2 mm long, linear. Anthers 0.9–1.3 mm long. Seed c. 2.0 × 0.7(–1.0) mm.