Plants annual, 4--12 cm tall. Stems usually many, erect or ascending, often weak. Leaves basal and cauline; leaf blade flat and margin convolute to subterete, 1.5--5 cm × 0.5--1 mm; leaves below inflorescence 1--4. Inflorescences of capitate clusters or occasionally lax; involucral bract leaflike. Bracteoles 2, broadly ovate, 1.5--2 × ca. 1.5 mm. Perianth segments whitish, lanceolate; outer segments 3--5 × 1--1.4 mm, center green and thick, margin membranous, apex acute; inner segments 2.8--3.3 × 0.3--1.2 mm, mostly scarious, apex obtuse to rarely acute. Stamens 6; filaments 0.8--1.3 mm; anthers 0.3--0.7 mm. Style absent; stigmas ca. 0.5 mm. Capsule trigonous ellipsoid, 2.9--4 mm, slightly longer than inner perianth segments, apex obtuse. Seeds broadly ellipsoid to ovoid, 0.4--0.5 mm, base and apex obtuse. Fl. May--Jun, fr. Jul--Sep. 2 n = 34.

The Chinese material placed here may in fact be the C Asian species Juncus turkestanicus V. I. Kreczetowicz & Gontscharow ( J. bufonius Linnaeus subsp. turkestanicus V. I. Kreczetowicz & Gontscharow) Novikov).

Streamsides, near ditches and hot springs; 2300--4300 m. Gansu, Jiangsu, Nei Mongol, Qinghai, Yunnan, Xinjiang [Mongolia; Europe].