Description from Flora of China
Pyrola uniflora Linnaeus, Sp. Pl. 1: 397. 1753; Bryophthalmum uniflorum (Linnaeus) E. Meyer; Chimaphila rhombifolia Hayata; Moneses grandiflora Salisbury; M. rhombifolia (Hayata) Andres.
Herbs evergreen. Rhizome creeping, slender, 0.2–0.6 mm in diam.; roots long, slender, branched. Aerial stems erect or ascending, terete to angular, 1–5 cm, 0.6–1 mm in diam., not branched, glabrous. Leaves in 3 or 4 subverticils of 2 or 3 each, alternating with ca. 5 scales; petiole (0.5–)1–1.5 cm; leaf blade abaxially pale green, adaxially deep green and slightly shiny, broadly rhombic, 1–1.6 × 1–1.5 cm, abaxially glabrous, base subrounded to broadly cuneate, margin minutely toothed, apex rounded to obtuse. Flower nodding,
regular, opening fully. Scape erect, (4–)5–10 cm tall, 1-flowered, glabrous. Bracts 1 or 2 on upper part of scape, 4–5 × ca. 2 mm, ciliolate. Sepals (4 or)5, ovate-elliptic, ca. 2.5 mm, ciliolate, apex rounded. Petals (4 or)5, white, orbicular to broadly ovate, sessile. Stamens (8–)10; anthers 3–4 mm, tubes distinct and strongly curved. Ovary subglobose; style 4–5 mm; stigma peltate with 5 distinct marginal papillae. Capsules subglobose, 5–6 mm in diam., fibers absent at margin. Seeds narrowly fusiform; testa generally with 7 or 8 cells along longest axis, inner testa walls with scalariform pits. Fl. Jul, fr. Sep. 2n = 26.
Moist mossy coniferous forests, more rarely in wet Betula or Pinus woods; middle elevations. Gansu, Heilongjiang, Jilin, Shanxi, N Sichuan, Taiwan, Xinjiang, NW Yunnan [Japan, N Korea, Mongolia, Russia; widely distributed in N temperate and subarctic zones, particularly Europe].