Arenaria perlevis (F. N. Williams) Handel-Mazzetti; A. polytrichoides Edgeworth var. perlevis F. N. Williams.

Herbs perennial. Roots conic, slender. Stems in small, compact, subglobose clusters, pulvinate, branched at base, 4--5 cm, with crowded, withered, persistent leaves at base. Leaf blade subulate-elliptic or ovate-subulate, 3--6 × ca. 1 mm, base clasping, membranous, margin flat distally, hard, ciliate, apex acute, mucronulate. Flower solitary, terminal, 6--7 mm in diam. Sepals 5, ovate or ovate-lanceolate, 2--2.5 × ca. 1 mm, ca. 1/2 as long as petals, 3-veined, midvein raised, lateral veins short, base rounded, incrassate, margin hard, scarious, apex obtuse. Petals 5, white, saccate or obovate, 4--5 × ca. 1.5 mm. Stamens 10; filaments opposite sepals with a gland at base; anthers yellow. Ovary obovoid, ca. 1.5 × 1 mm. Styles 3, less than 1 mm. Fl. Jul.

Alpine meadows, gravels; 4200--5000 m. SE Xizang [Bhutan, India, Nepal, Sikkim].