凹脉薹草 ao mai tai cao

Rhizome with ligneous and slender stolons. Culms 20-50 cm tall, triquetrous, rather slender, smooth on lower part and scabrid near top, clothed with red-brown and bladeless sheaths at base, one side of sheaths disintegrating into reticulate fibers. Leaves slightly longer than or equaling culm, blades 2-3 mm wide, stiff, longitudinally furrowed on costa, involute on margins, mid-sheathed. Involucral bracts leafy, lower involucral bracts longer than inflorescence, shortly sheathed, upper involucral bracts rather short, nearly not sheathed. Spikes 3-6; terminal 1-3 male, slightly contiguous, clavate, 1-2.5 cm, nearly sessile; remaining spikes female, remote, ovate or oblong, 1-3 × ca. 1 cm, slightly densely many flowered, pedunculate, peduncle less than 1 cm. Female glumes fuscous laterally, pale at middle, ovate or narrowly ovate, 4.5-5 mm, membranous, costate, apex acuminate, aristate. Utricles brown-green, obliquely patent, longer than glume (excluding awn), ovoid, slightly inflated trigonous, ca. 5 mm, leathery, glabrous, with several rather concave veins, base broadly cuneate, apex abruptly contracted into a slightly broad and short beak, orifice shortly 2-toothed, teeth straight, smooth. Nutlets broadly obovate or subelliptic, trigonous, ca. 2 mm, base stipitate, apex slightly long mucronate; style base not thickened; stigmas 3. Fl. and fr. Apr-Jun.

Solonchalk or solonetz soil in grasslands, damp places in valleys; ca. 1300 m. Xinjiang [Russia; C Asia, C Europe].