Description from
Flora of China
Juncus prismatocarpus R. Brown var. leschenaultii (J. Gay ex Laharpe) Buchenau subvar. unitubulosus Buchenau; J. pseudokrameri Satake.
Plants perennial, densely tufted, 25--40 cm tall. Stems terete, 1--2 mm in diam. Basal leaves 1 or 2, cauline leaves 2; leaf sheath auricles obtuse, 0.6--1 mm; leaf blade terete, 3--15 cm × 1--2 mm, hollow, distinctly septate. Inflorescences terminal; involucral bract leaflike, usually shorter than inflorescence; heads usually more than 25, hemispheric, 2--5 mm in diam., (2--)4--6(--10)-flowered. Perianth segments chestnut brown, lanceolate, 2--2.8 × ca. 0.8 mm, often unequal with inner ones larger than outer, margin scarious, apex mucronate to acuminate. Stamens 3; filaments ca. 1 mm; anthers ca. 0.7 mm. Capsule dark chestnut brown, shiny, trigonous oblong, 2.8--3.5 mm, apex cuspidate. Seeds reddish brown, ca. 0.5 mm. Fl. Jul--Aug, fr. Aug--Sep.
The stems and leaves are used for paper making and knitting.
Riversides, swamps, meadows, moist roadsides; 800--2900 m. Fujian, Gansu, Guangdong, Hainan, Heilongjiang, Jilin, Liaoning, Nei Mongol, Shandong, Taiwan, Yunnan, Zhejiang [Bhutan, India, Japan, Korea, Nepal, Russia (Siberia), Sikkim, Sri Lanka].