Description from Flora of China
Deutzia pilosa var. longiloba P. He & L. C. Hu; D. pilosa var. longiloba W. T. Wang ex S. M. Hwang (1992), not P. He & L. C. Hu (1990).
Shrubs 1-1.8 m. Flowering branchlets 6-8 cm, 4-6-leaved, stellate hairy, hairs with long central rays. Petiole 1-3 mm; leaf blade abaxially greenish, ovate, ovate-lanceolate, or oblong-ovate, 3-9.5 × 1.5-5 cm, papery, abaxially 6- or 7(or 8)-rayed stellate hairy, hairs with long central rays, adaxially 4- or 5(or 6)-rayed stellate hairy, veins in 3 or 4 pairs, reticulate veins slightly sparse, elevated abaxially, base rounded or broadly cuneate, margin serrulate, apex acuminate or caudate. Corymbose cymes 3-5 × 4-6 cm, 3- or 4-flowered; pedicels 3-10 mm. Calyx tube ca. 3 × 3.5 mm, densely 8-12-rayed stellate hairy, hairs with central rays; lobes ovate or ovate-lanceolate, 1.5-4 mm, apex acute or acuminate. Petals induplicate, white, ovate-oblong, 8-10 mm. Outer stamens 4-5 mm; filaments 2-dentate at apex, teeth spreading, exceeding anthers. Inner stamens 3-4 mm; filaments 2-lobed or acuminate at apex; anthers borne near middle on filaments abaxially. Styles 3(or 4), ca. 2.5 mm. Capsule subglobose, ca. 5 mm in diam., with persistent, incurved calyx lobes. Fl. Apr-May, fr. Jun-Aug.
* Forest margins, mountain slopes; 400-2000 m. Gansu, Guizhou, ?Shaanxi (Qin Ling), Sichuan, Yunnan.