双柱头针蔺 shuang zhu tou zhen lin

Scirpus pumilus Vahl subsp. distigmaticus Kükenthal, Acta Horti Gothob. 5: 34. 1930; Baeothryon distigmaticum (Kükenthal) Y. C. Yang & M. Zhan; S. distigmaticus (Kükenthal) Tang & F. T. Wang.

Plants dioecious. Rhizomes creeping, long, slender. Culms 10-25 cm tall, slender, subterete, smooth. Leaf sheath brown, to 2.5 cm, longer than blade; leaf blade setaceous, to 1.8 cm but basal 2 or 3 bladeless. Inflorescences reduced to a single terminal spikelet, ovoid, ca. 5 × 2.5-3 mm, few flowered. Glumes straw-colored, ovate, ca. 3.5 mm, thinly membranous, shiny, margin sometimes basally white but apically brown, apex obtuse. Perianth bristles absent. Stamens 3, sterile on female flowers. Style long; stigmas 2. Nutlet black at maturity, broadly obovoid, ca. 2 mm, plano-convex. Fl. and fr. Jul-Sep.

Alpine grasslands, river margins; 2000-4600 m. Gansu, Ningxia, Qinghai, Shaanxi, Sichuan, NE Xizang, Yunnan [Africa, Australia, Europe].