4. Eriophorum gracile W. D. J. Koch ex Roth, Catal. Bot. 2: 259. 1800.
细秆羊胡子草 xi gan yang hu zi cao
Eriophorum asiaticum V. N. Vassiljev; E. coreanum Palla; Scirpus ardea T. Koyama; S. ardea var. coreanus (Palla) T. Koyama.
Rhizomes long creeping, slender. Culms scattered, 25-50 cm tall, slender, ± 3-angled, smooth or sometimes scabrous below inflorescence. Basal leaves narrowly linear, ca. 1 mm wide, compressed 3-angled, channeled only in basal part. Cauline leaves ± short (apicalmost with blade shorter than sheath), 1.5-2.5 cm. Involucral bracts 1 or 2, dark green, sheathlike, ca. 1.5 cm, erect or oblique. Inflorescence a simple anthela with 2-4 spikelets. Spikelets obovoid, 6-10 mm in flower; peduncles unequal, ca. 2 cm, flattened, scabrous, yellow tomentose, partly dropping. Glumes dark black to gray, broadly ovate, 4.5-5 mm, many veined, keeled, margin hyaline, apex obtuse. Perianth bristles 10 or more, whitish, 1-1.5 cm. Stamens 3; anthers 2-3 mm. Style slender; stigmas 3. Nutlet yellowish brown, oblong, ca. 3 mm, compressed 3-sided. Fl. and fr. Jun-Jul. 2n = 60.
Marshes, meadows; (below 100-)700-2200 m. Heilongjiang, Jilin, N Liaoning, NE Nei Mongol, N Sichuan, N Xinjiang, Yunnan (Tengchong) [Japan, Kazakhstan, Korea, Russia; Europe, North America].