Description from Flora of China
Dichroa tristyla W. T. Wang & M. X. Nie; Hydrangea minnanica W. D. Han; H. vinicolor Chun.
Shrubs 0.7-2.5 m tall. Branchlets dark purple-brown, terete, glabrous or slightly crisped pubescent when young; bark peeled off into fragments when old. Petiole 5-10 mm, sparsely pubescent or glabrous; leaf blade dark purple-red to dark brown on both surfaces when dry, adaxially glossy, lanceolate to narrowly elliptic, 5-9(-18) × 1.5-2.5(-4.5) cm, papery, both surfaces glabrous, secondary veins 5-7 on both sides of midvein, abaxially slightly elevated, adaxially inconspicuous, base cuneate to obtuse, margin sparsely serrulate, apex caudate-acuminate. Inflorescences corymbose cymes, 5-7 cm wide, densely pubescent. Sterile flowers absent. Fertile flowers few. Calyx tube cupular, ca. 1 mm; teeth ovate-triangular to lanceolate, 0.5-2 mm. Petals yellowish, narrowly elliptic, obovate, or broadly so, 2.5-3 mm, with 1 midvein and sometimes 2 secondary veins, base with a claw ca. 1 mm. Stamens 8-10, subequal, 2.5-4 mm; anthers oblong, ca. 1.5 mm. Ovary ca. 1/2 superior. Styles 3, erect or slightly spreading, 1.5-2 mm in fruit; stigmas not to slightly decurrent along style adaxially. Capsule cupular, 3-4 mm in diam., projected apical part 1.5-2 mm, subequaling calyx tube. Seeds brown, ellipsoid, obovoid, or subglobose, 0.5-0.7 × 0.4-0.5 mm, wingless; seed coat net veined. Fl. Apr-May, fr. Aug-Nov.
* Dense to sparse forests or thickets in valleys or on mountain slopes; 200-900 m. W Fujian, EC Guangdong, E Guangxi, Guizhou, Hunan, Jiangxi.