Arenaria trichotoma Royle ex Edgeworth & J. D. Hooker in J. D. Hooker, Fl. Brit. India 1: 235. 1874, not Boissier (1856); A. lanceolatifolia L. H. Zhou.

Herbs perennial. Roots robust, woody. Stems caespitose, trichotomously branched, 50--60 cm, glandular villous. Leaf blade lanceolate, 1--2.5 cm × 1--4 mm, glandular villous, base clasping, apex acute. Cymes trichotomously branched, conic, many flowered; bracts ovate-lanceolate, similar to leaves but smaller, margin broadly membranous. Pedicel 0.5--3 cm, glabrous. Sepals 5, ovate, 3.3--5 × 1.5--3 mm, glabrous, midvein raised, base broadened, margin narrowly membranous, apex acute. Petals 5, white, obovate or elliptic, equaling or slightly longer than sepals. Stamens 10, 5 long and 5 short. Ovary obovoid, ca. 3 mm. Styles 3, linear, ca. 2 mm. Seeds with flat wings. Fl. Jun--Jul.

Mountain gravels; 2600--3500 m. W Xizang [Afghanistan, NW India, Pakistan].