Description from Flora of China
Epilobium parviflorum var. vestitum Bentham ex C. B. Clarke.
Herbs robust, perennial, with short-stalked leafy basal rosettes. Stems 18-100(-160) cm tall, well-branched above, densely gray villous on lower part, mixed above with short glandular hairs, often with raised lines decurrent from margins of petioles. Leaves subsessile or lower ones with petioles 1-3 mm; cauline blade lanceolate-elliptic to narrowly lanceolate or oblong-lanceolate, 3-12 × 0.5-2.5 cm, both surfaces villous, base usually rounded, margin denticulate with 15-60 teeth per side, apex subacute. Inflorescence and flowers erect. Sepals 2.5-6 mm, keeled. Petals bright pink to dark purple, 4-8.5 mm. Stigma deeply 4-lobed. Capsules 3-7 cm, pubescent or rarely glabrescent; pedicels 0.5-1.8 cm. Seeds dark brown, 0.8-1.1 mm, coarsely papillose, with inconspicuous chalazal collar; coma tawny or dull white, detaching easily. Fl. Jun-Sep, fr. Jul-Oct. 2n = 36.
Usually in disturbed wet places near streams, bogs, and rivers, open waste slopes and meadows in mountains; (300-)500-1800(-2500) m. Gansu, Guizhou, Hebei, Henan, Hubei, Hunan, Nei Mongol, Shaanxi, Shandong, Shanxi, Sichuan, Xinjiang, Yunnan [Afghanistan, India, Japan, Korea, Nepal, Pakistan, Russia; Africa, SW Asia, naturalized in New Zealand, North America].