本兆荸荠 ben zhao bi qi

Perennials. Rhizomes elongate. Culms tufted, erect, 25-35 cm tall, ca. 2 mm thick. Leaf sheaths 1(or 2), grayish brown, tubular, 5-7 cm, smooth, glabrous, mouth truncate. Spikelet oblong, ca. 8 × 3-4 mm, more than 10-flowered. Basalmost glume empty, amplexicaul for more than 1/2 of spikelet base; fertile glumes brown, sublaxly imbricate, ovate to narrowly ovate, ca. 4 × 2 mm, margin ± broadly hyaline, apex acute to obtuse. Perianth bristles 4, slightly longer than nutlet, retrorsely spinulose. Stigmas 2. Nutlet yellowish, obovoid, ca. 1.7 × 1.5 mm, biconvex, smooth, both sides narrowly margined, apex constricted; persistent style base white but dark brown at apex, obtusely 3-angled, nearly as long and ca. 1/3 as wide as nutlet, spongy. Fl. and fr. Jul-Aug.

● Shallow water at lake margins; ca. 3300 m. Qinghai (Qinghai Hu).