Description from Flora of China
Cassiope mairei H. Léveillé.
Shrubs 10–20 cm tall. Stems initially decumbent, ultimately erect, glabrous or pubescent. Leaves assurgent; leaf blade ovate-triangular, 2–3 × 1–1.5 mm, cymbiform, leathery, abaxially deeply furrowed, furrow nearly reaching apex and divergent near base, furrow rim densely pubescent, adaxially concave, glabrous, margin not membranous, fringed with wool-like hairs, glabrescent. Flower nutant. Pedicel 0.5–1.6 cm, densely crisped-tomentose. Calyx crimson or reddish brown; lobes oblong to elliptic, ca. 3.8 mm, glabrous or puberulous, margin membranous, inconspicuously ciliolate. Corolla pure white, reddish within at base, broadly campanulate, 6–8 mm; lobes erect, oblong, 2.5–3 mm. Stamens ca. 2.5 mm; filaments pilose; awns ca. 0.9 mm. Capsule 2–3 mm in diam. Fl. May–Jul, fr. Jun–Sep.
Rhododendron thickets, alpine grasslands, rocky slopes, cliffs; 3000–4200(–4500) m. W Sichuan, SE Xizang, NE Yunnan [Bhutan, Myanmar, Nepal, Sikkim].