Needlegrass

This is a widespread and highly polymorphic species. Variation in China is best accommodated within the following two subspecies. Stipa caucasica subsp. glareosa has a rather more easterly distribution, but smaller, scabrid-leaved forms occur sporadically throughout the range of the species in part related to increased altitude. The species is close to S. orientalis, the most obvious difference being the 1-geniculate awn. Hybrids between S. caucasica and S. orientalis have been reported.

Collected several times in Kashmir at about 5000 m. It is the only species of Stipa (sensu str.) in our flora to have a unigeniculate awn with a rigidly falcate bristle.

Densely tufted perennial, roots thick, tomentose, clothed in sand grains; old basal sheaths forming large clumps. Culms 15–30 cm tall, 2–3-noded, lower internodes pubescent. Basal leaves 2/3 length of culms; leaf sheaths shorter than internodes; leaf blades acicular, convolute, outer surface smooth or scabrid, ligule of basal leaves truncate, ca. 0.5 mm, of culm leaves rounded, 1–1.5 mm, ciliate. Panicle narrow, 5–10 cm, branches enclosed in inflated uppermost leaf sheath. Spikelets pale green-brown sometimes faintly purple-tinged; glumes equal or lower glume slightly longer, narrowly lanceolate, 1.5–4 cm, apex long attenuate-filiform; callus pungent, 1–2 mm; lemma 7–10 mm, pilose in longitudinal lines, a ring of soft hairs at apex; awn deciduous, 5–12 cm, hairy throughout, 1-geniculate, column 1.5–2.3 cm, hairs 1–2 mm, bristle 5–8 cm, falcately curved, plumose, hairs 3–5 mm. Fl. and fr. Apr–Jun.

Tufted perennial (10-)25-70 cm high. Leaf-blades involute and setaceous, stiff and pungent, up to 3.5 mm wide when flattened, glabrous and smooth on the lower (outer) surface; ligule shaggy, 05-0.7 mm long. Panicle narrow, contracted, 5-10(-17) cm long, partially enclosed by the inflated sheath of the uppermost leaf or between the inflated sheaths of the two uppermost leaves. Glumes subequal, lanceolate and long-acuminate, 25-50 mm long, 5-nerved; lemma terete, 9-13 mm long (including callus), hairy with long or short hairs in distinct rows and with a crown of short hairs at the tip; callus acuminate, pungent, 2-3 mm long. Awn unigeniculate, articulated at the base, (4.5-)8-13.5 cm long; column bearing hairs 1-3 mm long; bristle rigidly falcate, plumose with hairs 4-6 mm long.

Gansu, Hebei, Henan, Nei Mongol, Ningxia, Qinghai, Shaanxi, Xinjiang, Xizang [Afghanistan, Kashmir, Kazakhstan, Kyrgyzstan, Mongolia, Russia (Siberia), Tajikistan, Turkmenistan; SW Asia (Caucasus, N Iran)].

Distribution: Kashmir; Caucasus eastwards to Central Asia.

Fl. & Fr. Per.: August-September.

Stony mountain slopes, sand dunes, gravel plains; 1400–5100 m.