Deschampsia flexuosa (L.) Trin.

Common exposed gravelly soil in alpine zone, and rocky slopes in montain regions.

A variant of this widespread species found on Yu Shan (Mt. Morrison) in Taiwan has larger spikelets than usual (6–8 mm), since the glumes are drawn out into long caudate tips, with the upper glume 1–2 mm longer than the lower. This variant is the basis of Deschampsia kawakamii. Typical D. flexuosa also occurs in Taiwan.

Culms tufted, slender, less than 30 cm tall. Blade filiform; ligule tongue-shaped, 2 mm long. Panicle open, loose, purplish, 5-12 cm long. Spikelets 2-several-flowered, 5 mm long; glumes lanceolate, acute; the lower 5 mm long, 3-nerved, lateral nerves shorter; the uppe glumes 4 mm long, 1-nerved.Floret 4 mm long, basal part covered with short hairs which are 1/3 the length of the floret; lemma rounded at the apex, as long as the floret, with a bent awn arising from below the middle; palea slightly shorter than the lemma, minutely 2-tooted, 2-keeled on back. Anthers 2 mm long. Caryopsis glabrous, 2.5 mm long.

Perennial, tufted, sometimes rhizomatous; old basal sheaths tightly overlapping. Culms slender, erect, 15–60 cm tall, 2- or 3-noded. Leaf sheaths longer than internodes, smooth or scaberulous upward; leaf blades setaceous, rather stiff, 3–15 cm, 0.3–0.5 mm wide, abaxial (outer) surface smooth; ligule lanceolate, 2–4 mm. Panicle open, ovate in outline, 5–10 cm, silvery with purple or brown tinge; branches usually paired, capillary, flexuous, bearing spikelets on distal part. Spikelets 4–6(–8) mm, florets 2, rachilla internode short; glumes thinly membranous, 1-veined, lower shorter than upper, apex acute; callus hairs ca. 1 mm; lemmas 3.5–5(–6) mm, asperulous, awned from near base, apex denticulate or erose; awn 5–8 mm, exserted from spikelet, geniculate in middle, column dark brown, twisted. Anthers 1.5–2.5 mm. Fl. and fr. Jul–Sep. 2n = 28.

Widespread in Europe, mountains of Asia, America.

Widely distributed in Eurasia and N. America.

3000 m

Exposed mountain peaks, on stony soil and rocky slopes. Taiwan [Japan, Philippines (Luzon), Russia; Africa (high mountains), SW Asia (Caucasus), Europe, North America, South America (S Argentina, S Chile)].

Aira flexuosa L., Sp. Pl. 1: 65. 1753. Aira kawakamii Hayata, Bot. Mag. Tokyo 20: 57. 1906; Icon. Pl. Form. 7: 90. 1918. Deschampsia kawakamii (Hayata) Honda, Monogr. Poac. Jap. 140. 1930.

Aira flexuosa Linnaeus, Sp. Pl. 1: 65. 1753; A. kawakamii Hayata; Avenella flexuosa (Linnaeus) Drejer; Deschampsia kawakamii (Hayata) Honda; Lerchenfeldia flexuosa (Linnaeus) Schur.