Herbs annual, glabrous. Stems tufted, ascending, 12(--20) cm tall, slender. Leaves sessile, linear to linear-lanceolate, 5--15 × (0.8--)1.5--2(--4) mm, both surfaces glabrous, midvein conspicuous, base rounded, apex obtuse. Flowers 2--4, in cymose umbel; bracts ovate, ca. 2 mm, membranous. Pedicel 1.2--2.4 cm, slender. Sepals 5, green, ovate-lanceolate, ca. 2 mm, 3-veined, margin broadly membranous, apex acute. Petals absent. Stamens 5; filaments slender. Styles 3, short. Capsule ovoid, ca. 4 mm, ca. 2 × as long as persistent sepals, 6-valved. Seeds pale brown or dark brown, compressed orbicular, with granular protuberances. Fl. Jun--Jul, fr. Jul--Aug.

Species nos. 53–57 are members of Stellaria sect. Adenonema (Bunge) Turczaninow. This group is in need of thorough revision. There are now several different ideas on which of these taxa should be recognized. It is also possible that additional taxa may (or may not) belong to this section.

In addition, Kozhevnikov described Stellaria divnogorskajae (Novosti. Sist. Vyssh. Rast. 20: 103. 1983) based on a specimen from Kaschgaria (Xinjiang). It is similar in size to S. arenarioides (stems 5–7 cm), with oblong-elliptic leaves, 4- or 5-merous flowers, 2 styles, and a 4-valved capsule. He also described S. divnogorskajae var. pilosa (Novosti Sist. Vyssh. Rast. 20: 104. 1983) based on a specimen from Tagdumbasch-Pamir (Xinjiang), noting that the plant is pilose throughout. The present authors have seen no material of either taxon.

Montane meadows, rocky crevices, cushionlike scrub; 3500--5000 m. Sichuan, Xizang, Yunnan [India, Kashmir, Nepal, Sikkim].