Juncus alatus Franch. & Sav.

Plants perennial, tufted, 11--50 cm tall. Rhizome short. Stems flat, 2--4 mm wide, laterally broadly winged. Basal leaves 2--4, cauline leaves 1 or 2; leaf sheath auricles small, rounded, membranous; leaf blade flat, 5--16 cm × 3--4 mm, usually incompletely septate. Inflorescences terminal, 3--12 cm, sparingly branched; heads (4--)7--27, 3--7-flowered; bracts 2 or 3, broadly ovate, 2--2.5 × ca. 1.5 mm, membranous, apex acute. Perianth segments greenish to chestnut brown, lanceolate, 3--3.5 × 1--1.3 mm, margin scarious, apex acuminate. Stamens 6; anthers 0.5--0.8 mm, ca. 1/2 as long as filaments. Ovary ellipsoid, 1-loculed. Capsule chestnut brown, 3.5--5 mm. Seeds ellipsoid, 0.4--0.5 mm, longitudinally striate. Fl. Apr--Jul, fr. May--Oct.

Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shandong, Shanxi, Sichuan, Yunnan, Zhejiang [Japan, Korea].

Forests on mountain slopes, fields, swampy meadows, riversides, moist to wet streamsides, ditches; 100--2300 m.