Description from Flora of China
Philadelphus coronarius Linnaeus var. tomentosus (Wallich ex G. Don) J. D. Hooker & Thomson.
Shrubs 2-3 m tall. Branchlets of previous year gray-brown, those of current year black-brown, glabrous or sparsely villous. Petiole 5-8 mm; leaf blade ovate or ovate-lanceolate, 4-10 × 2-5 cm, abaxially densely gray-yellow villous, adaxially glabrous, veins 5-7, slightly basifugal, base rounded or broadly cuneate, margin remotely serrulate, apex caudate-acuminate, acumen 1.5-2.5 cm. Racemes 5-7-flowered, lowest 1 or 2 pairs 3-flowered; rachis 5-10 cm, glabrous; pedicels 6-11 mm, villous or glabrous. Calyx tube sparsely villous or glabrescent; lobes ovate, 4-5 × 2.5-3.5 mm, apex acuminate. Corolla cruciform; petals white, obovate-oblong, 5-10 × 5-8 mm. Stamens 20-25, longest ones ca. 8 mm. Disc glabrous. Style apically divided for ca. 1/3 its length, ca. 7 mm; stigmas clavate, 1.5-2 mm, longer than anthers. Capsule ellipsoid, ca. 1 × 0.7 cm. Seeds ca. 4 mm, shortly tailed. Fl. Jun-Jul, fr. Aug-Sep.
Forests, thickets; 2500-4400 m. Xizang, Yunnan [Bhutan, India, Kashmir, Nepal, Sikkim].