11. Kobresia filifolia (Turczaninow) C. B. Clarke, J. Linn. Soc., Bot. 20: 381. 1883.
丝叶嵩草 si ye song cao
Elyna filifolia Turczaninow, Bull. Soc. Imp. Naturalistes Moscou 28(1): 353. 1855; Kobresia capillifolia (Decaisne) C. B. Clarke var. filifolia (Turczaninow) Kükenthal; K. filifolia var. macroprophylla Y. C. Yang; K. gracilis Meinshausen; K. macroprophylla (Y. C. Yang) P. C. Li; K. pratensis Freyn.
Rhizomes short. Basal sheaths prominent and persistent, orange-brown, not retaining dried leaf blades, sometimes decaying to fibers. Culms densely tufted, obtusely trigonous, 15-50 cm, slender, 0.6-1 mm in diam. Leaves basal, shorter than or subequaling culms; blade filiform, weak, margin involute, 0.5-1.5 mm wide. Inflorescence a dense spikelike panicle (occasionally reduced to a spike), reddish brown or pale brown, cylindric, 1-3 × 0.3-0.7 cm, branches short, appressed; lowest involucral bract glumelike, apex aristate. Lower inflorescence branches with terminal spikelets male, lower spikelets bisexual. Bisexual spikelets 2-7-flowered, basal one female, other 1-6 male. Glumes reddish brown or brown, with yellowish brown midvein, ovate or ovate-oblong, (3-)4-4.5(-6.2) (excluding arista) × 1.5-2.8 mm, membranous, margin broadly hyaline, apex acute or aristate. Prophylls brown or yellowish brown, ovate-oblong or oblong-elliptic, 3-4 × 1-1.8 mm, membranous, 1- or 2-keeled, keels slightly scabrid, margins free to base, apex rounded or slightly 2-toothed. Nutlets dark brown, obovoid or oblong-obovoid, trigonous or biconvex, 2.1-3.5 (excluding beak) × 1-1.2 mm, very shortly stipitate, shortly beaked, beak slightly conic. Stigmas usually 3, occasionally both 3 and 2 on same inflorescence. Fl. and fr. May-Oct. 2n = ca. 60.
Wet grassy slopes, boggy meadows; 1700-2900 m. Gansu, Hebei, Nei Mongol, Qinghai, Shanxi [Mongolia, Russia].
Forms with simple (spicate) inflorescences are similar to Kobresia myosuroides subsp. bistaminata and to K. capillifolia (both of which share the bistigmatic tendency). Such forms differ from both taxa in having weaker leaves; and they differ from the latter in having dull, orange-brown, shorter basal sheaths and usually more than 2 male flowers per spikelet.