Description from Flora of China
Shrubs deciduous, 0.4–2 m tall, many branched. Twigs flattened-angular, glabrous; bud scales inconspicuous. Leaves scattered; petiole 1–2 mm, glabrous or abaxially pubescent; leaf blade sometimes reddish when young, ovate or ovate-lanceolate, (1.5–)2–6 × 0.7–2 cm, papery, abaxially subglabrous or pubescent towards base of midvein, adaxially glabrous or rarely pubescent, secondary veins 2–4 pairs, ± ascending, raised abaxially, inconspicuous and impressed adaxially, fine veins raised abaxially, impressed adaxially, base broadly cuneate to subtruncate, margin plane, setose-serrulate, apex acute or acuminate for ca. 0.5 cm. Flowers solitary, axillary, pendulous, at base of young shoot. Pedicel 5–8 mm, slender, glabrous. Flowers 4-merous. Hypanthium glabrous; calyx limb divided nearly to base; calyx lobes triangular, 1–1.8 mm, apex abruptly acuminate. Corolla white or pinkish, glabrous, lobed nearly to base; lobes linear-lanceolate, 0.8–1 cm, margin revolute. Filaments 1–2 mm, often densely villous; anthers 6–7 mm, thecae without spurs; tubules ca. as long as thecae. Berry 4-loculed, red, ca. 5 mm in diam. Fl. Jun–Jul, fr. Aug–Oct.
Two varieties occur in China; var. japonicum is endemic to Japan.
Forests, thickets, alpine areas; 1000–2600(–3000) m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan, Taiwan, Yunnan, Zhejiang [Japan].