Description from Flora of China
Carex capillacea var. linzensis Y. C. Yang; C. capillacea var. yunnanensis Franchet; C. rara Boott var. capillacea (Boott) Kükenthal; C. rara f. yunnanensis (Franchet) Kükenthal.
Rhizome short. Culms tufted, 15-40 cm tall, slightly scabrous above. Leaves shorter than culm, blades threadlike, 0.5-1 mm wide, flat or involute, smooth; basal sheaths split into brown fibers. Inflorescence 1-spiked, terminal, androgynous; male part distinct, linear, 4-7 mm, 3-7-flowered; female part ovate-orbicular, 3-6 mm, densely 4-10-flowered. Female glumes brown laterally and diluted at middle, elliptic-ovate, ca. 2 mm, 1-3-veined, apex rounded-obtuse. Utricles horizontally patent at maturity, slightly longer than glume, lanceolate-ovate, swollen, trigonous, 2.5-3 mm, with distinct marginal veins and faint veins at middle, sometimes with rusty spots, base rounded-obtuse, apex gradually attenuate into a short beak, orifice slightly emarginate or minutely 2-toothed. Nutlet loosely enveloped, elliptic, trigonous, ca. 1.8 mm; style base not thickened, persistent; stigmas 3. Fl. and fr. Apr-May.
Wet grasslands on mountain slopes, streambanks. Anhui, Fujian, Jiangxi, Taiwan, Yunnan, Zhejiang [Indonesia, Japan, Myanmar, Philippines, Thailand].