Perennials, 12–20 cm tall, loosely caespitose; rhizome short-noded, horizontal; sterile shoots present. Stem erect, terete, 0.4–0.8 mm in diam. Cataphylls 1–2, green to brownish, to c. 2.5 cm long; leaves flat, grass-like. Sub-basal and basal leaves 1–3, 5–15 cm long, c. 1.5–3.5 mm wide; sheath 2–4 cm long. Cauline leaves 1–2, 5–12 cm long, 1.4–3 (–5) mm wide; auricles obtuse, c. 0.5 mm long, scarious to brownish. Lower bract leaf-like, flat, 3–10 cm long, exceeding inflorescence; capitulum bracts white, ovate-lanceolate, 2.5–4.5 mm long. Inflorescence anthelate, decompound, with 1–4 main branches and frequent secondary ones, of 2–10 (–12) white hemispherical 3–8-flowered heads 5–9 mm wide. Pedicels 0.5–1.0 mm long.Tepals ±equal or inner ones slightly longer, lanceolate, subacute, (1.8–) 2.0–2.8 mm long, 0.6–0.8 mm wide, white. Stamens 6, long-exserted; anthers elliptic, yellowish white, 0.8–1.2 mm long; filaments to 4–8 mm long; style 1.0–1.5 mm long; stigmas 0.5–1.0 mm long, whitish. Capsule ellipsoid-ovoid, acuminate, rostrate, 3.5–5.5 mm long; rostrum exceeding perianth. Seeds ellipsoid, 0.6–0.7 × c. 0.2 mm, or c. 1.1–1.6 mm long including two appendages 0.3–0.5 mm long.
Sikkim and south-central regions of China. 36: CHC. 40: EHM.
36. CHINA SOUTH-CENTRAL: Sichuan, Tahsingling, 2700 m, H.Smith 10208 (UPS); Yunnan, Deqin Xian, Meili Xueshan, Suola, 3700 m, S.K.Wu & al. 193125 (KUN, TI); Yunnan, Zhongdian, Haba Shan, 3717 m, [anonymous: ACE] 329 (E); Yunnan, S of Zhongdian, 3215 m, [anonymous: ACE] 1603 (E). 40. EAST HIMALAYA: Sikkim Lachen, J.D.Hooker (K); Bhutan, Thimphu, Ragyo, N of Paro, 3450 m, H.J.Noltie 89 (E).
On mossy rocks in moist woodlands, above 2500 m.
Closely related to J. concinnus but leaves flat.