无芒薹草 wu mang tai cao

Rhizome absent. Culms 20-55 cm tall, trigonous, smooth, clothed with dark brown bladeless sheaths. Leaves shorter than culm, blades green, linear, 3-5 mm wide, flat, margins scabrous, apex acuminate; leaf sheath at mouth membranous. Involucral bracts glumelike, lowest setaceous. Spicate inflorescence cylindric, 2.5-4.5 × 1-1.5 cm; upper spikes dense, lower ones interrupted; spikes 8-14, androgynous, ovate, 5-8 mm. Female glumes ferruginous, ovate, 2-2.5 mm, membranous, 1-veined, margins sometimes pale hyaline, apex without awn. Utricles ferruginous-brown, longer than glume, ovate-lanceolate, plano-convex, 3-3.5 mm, many veined abaxially, 3- or 4-veined adaxially, scabrous in distal half, base rounded, spongy, margins thickened, apex gradually attenuate into a long beak, beak deeply cleft abaxially, subentire adaxially. Nutlets oblong, plano-convex, ca. 1.5 × 1 mm, base contracted into a short stipe; style base thickened; stigmas 2.

● Streambanks; ca. 2000 m. Gansu.