Deutzia is a genus of about 60 species of flowering plants in the family Hydrangeaceae, native to eastern and central Asia (from the Himalayas east to Japan and the Philippines), and Central America and also Europe. By far the highest species diversity is in China, where 50 species occur.
The species are shrubs ranging from 1–4 m (3 ft 3 in–13 ft 1 in) in height. Most are deciduous, but a few subtropical species are evergreen. The leaves are opposite, simple, with a serrated margin. The flowers are produced in panicles or corymbs; they are white in most species, sometimes pink or reddish. The fruit is a dry capsule containing numerous small seeds. Identification of the species is very difficult, requiring often microscopic detail of the leaf hairs and seed capsule structure.
Deutzia is named after the 18th century Dutch patron of botany, Johann van der Deutz.
Shrubs ca. 2 m tall. Flowering branchlets yellow-brown, very short initially, elongating to ca. 4 cm, 2-4-leaved, stellate hairy, hairs with central rays. Petiole 1-4 mm; leaf blade abaxially grayish, ovate-rhomboid or elliptic-ovate, 2-5.5 × 1-3.5 cm, papery, abaxially appressed 7-11-rayed stellate hairy, indumentum continuous, hairs along veins with central rays, adaxially 4-6-rayed stellate hairy, veins in 5 or 6 pairs, base cuneate or broadly so, margin irregularly serrulate, apex acute. Cymes 1-3 × 1-3 cm, 1-3(-5)-flowered; pedicels 3-12 mm. Calyx tube ca. 2.5 × 4 mm, densely gray-yellow stellate hairy, hairs sometimes with central rays; lobes linear-lanceolate, longer than tube, 1-1.5 mm wide. Petals induplicate, white, oblong or ovate-oblong, ca. 1.5 × 7 mm. Outer stamens 6-7 mm; filaments 2-dentate at apex, teeth horizontal or recurved, falcate; anthers stalked, ovoid-oblong. Inner stamens shorter than outer ones. Styles 3(or 4), subequaling stamens. Capsule hemispheric, 4-5 mm in diam., stellate hairy, with persistent, recurved calyx lobes. Fl. Apr-Jun, fr. Sep-Nov.
Thickets, mountain slopes, valleys; 800-1600 m. Gansu, Hebei, Henan, ?Hubei, Hunan, ?Jiangsu, Liaoning, ?Nei Mongol, Shaanxi, Shandong, Shanxi.