三脉嵩草 san mai song cao

Carex esenbeckii Kunth, Enum. Pl. 2: 522. 1837, based on C. trinervis Nees in Wight, Contr. Bot. India, 120. 1834, not Degland (1807); C. mutans Boott ex C. B. Clarke; Hemicarex hookeri (Boeckeler) Bentham; H. trinervis (Boeckeler) Bentham & J. D. Hooker ex C. B. Clarke; Kobresia angusta C. B. Clarke; K. foliosa C. B. Clarke; K. hookeri Boeckeler; K. hookeri var. dioica C. B. Clarke; K. seticulmis Boeckeler; K. trinervis Boeckeler.

Rhizomes short. Basal sheaths prominent and persistent, brown or dark brown, shiny, sometimes decaying to fibers, not retaining dried leaf blades. Culms densely tufted, erect, trigonous (sometimes obtusely), 3-32 cm tall, slender, 0.5-1 mm in diam. Leaves basal, ± equaling culms; blade flat, 1.5-5 mm wide, midrib distinct abaxially. Inflorescence spicate, unisexual or androgynous, male and female spikes sometimes borne on same plant; all spikelets 1-flowered (occasionally a few at base bisexual with a single male flower). Male spikes compact, 3.5-5 × ca. 0.4 cm; male glumes yellowish brown, narrowly oblong, 7-8.5 × 1.5-2 mm, 1-veined, margin broadly hyaline, apex obtuse. Female and androgynous spikes linear, 1.7-6.5 × 0.15-0.4 cm, spikelets usually loosely arranged; lowest involucral bract glumelike, apex aristate. Female glumes brown laterally, with green midvein, oblong or ovate, 2.2-4 × 1-2 mm, midvein narrow, margin narrowly hyaline, apex mucronate, acute, or obtuse. Prophylls utriculiform when young, splitting to base when mature, pale brown, linear-oblong, 2-3.7 × 0.4-0.7 mm, membranous, 2-keeled, keels ciliate, apex truncate and rounded. Nutlets narrowly oblong or elliptic, curved or not, very shortly stipitate and beaked, 2.5-3.7 (excluding beak) × 0.7-1 mm, stipe ca. 0.5 mm, beak 0.8-2 mm. Stigmas 3, twisted, white in field, thick. Sterile rachilla of female spikelets linear, minute, to 1/4 as long as nutlet. Fl. and fr. May-Oct.

Wet rocks, crevices of cliffs, grassy slopes, lakeshores, on trees; 2800-4300(-4900) m. Sichuan, Xizang, Yunnan [Bhutan, India (Himachal Pradesh, Sikkim, Uttarakhand), Myanmar, Nepal].