Description from Flora of China
Deutzia longifolia Franchet var. densitomentosa P. He & L. C. Hu.
Shrubs 1-2 m tall. Flowering branchlets 5-15 cm, 4-6-leaved. Petiole 3-5 mm; leaf blade abaxially grayish, lanceolate or elliptic-lanceolate, 5-8 × 1-1.5 cm, leathery, abaxially densely 12-16-rayed stellate hairy, indumentum continuous, hairs without long central rays, adaxially sparsely 6-8-rayed stellate hairy, veins in 4 or 5 pairs, base cuneate, margin serrulate, apex acuminate. Cymes aggregate, 4.5-5 × 3-6 cm, 9-18-flowered; pedicels 1-1.5 cm. Calyx purplish; tube ca. 3 × 3 mm, densely 12-18 rayed stellate hairy; lobes ovate-lanceolate, subequaling tube, leathery, midvein prominent. Petals induplicate, pink, obovate-elliptic, 8-10 × 4-6 mm. Outer stamens ca. 6 mm; filaments 2-dentate at apex, teeth exceeding anthers; anthers stalked, oblong. Inner stamens shorter than outer ones; filaments acute at apex; anthers borne near middle of filaments abaxially. Styles 3, subequaling stamens. Capsule brown, hemispheric, ca. 5 mm in diam., with persistent, recurved calyx lobes. Fl. Jun.
* Mixed forests; ca. 2000 m. S Sichuan (Leibo Xian).