Description from Flora of China
Deutzia grandiflora Bunge var. baroniana (Diels) Rehder; D. hamata Koehne ex Gilg & Loesener; D. hamata var. baroniana (Diels) Zaikonnikova; D. prunifolia Rehder.
Shrubs 0.3-1 m tall. Flowering branchlets brownish, 1-4 cm, 2-4 leaved, stellate hairy. Petiole 3-5 mm, stellate hairy; leaf blade ovate-rhomboid or ovate-elliptic, 2-5(-7) × 1.5-3(-4) cm, abaxially sparsely 5- or 6(or 7)-rayed stellate hairy, indumentum discontinuous, hairs along veins with central rays, adaxially 4- or 5-rayed stellate hairy, veins in 4 or 5 pairs, base cuneate or broadly so, margin irregularly serrulate or with alternating large and small teeth, apex acute. Cymes 1-1.5 × 1-1.5 cm, (1 or)2- or 3-flowered. Calyx tube ca. 2 × 4 mm, densely 4-6-rayed stellate hairy, hairs with central rays; lobes linear-lanceolate, 5-9 mm. Petals induplicate, white, obovate-oblong or -lanceolate, 1.5-20 × 5-7 mm. Outer stamens 6-7 mm; filaments 2-dentate at apex, teeth horizontal or recurved, falcate; anthers stalked, oblong. Inner stamens 3.5-4.5 mm. Styles 3 or 4, ca. 1.2 cm. Capsule hemispheric, ca. 4 mm in diam., with persistent, recurved calyx lobes. Fl. Apr-May, fr. Sep-Oct.
* Thickets, mountain slopes; 500-1200 m. Hebei, Henan, Jiangsu, Liaoning, Shaanxi, Shandong, Shanxi.