Description from Flora of China
Hydrangea aspera D. Don subsp. robusta (J. D. Hooker & Thomson) E. M. McClintock; H. longialata C. F. Wei; H. maximowiczii H. Léveillé; H. rosthornii Diels; H. rotundifolia C. F. Wei.
Shrubs or small trees, 2-3(-6) m tall. Branchlets, petioles, and inflorescences densely yellow-brown shortly hispid to spreading hirsute. Branchlets brown, usually 4-angled, glabrescent. Petiole thick, 3-15 cm; leaf blade elliptic, broadly so, or oblong-ovate to broadly ovate, 9-35 × 5-22 cm, papery, abaxially densely gray-white pubescent to sparsely brownish hispidulous, hairs sometimes longer and thicker along veins especially midvein, adaxially strigose, secondary veins 8-13 on both sides of midvein, base obtuse, truncate, rounded, or subcordate, margin irregularly doubly serrate, apex acute to acuminate. Inflorescences corymbose cymes, lax, long, to 30 cm wide in fruit; peduncle thick, 4-angled. Sterile flowers with sepals 4(or 5), purplish to white, broadly ovate, orbicular, or broadly orbicular, 1.2-3.8 × 1.3-3.5 cm, margin entire, dentate, or serrate. Fertile flowers with calyx tube cupular, 1-1.5 mm; teeth ovate-triangular, 0.5-1 mm. Petals purple, ovate-lanceolate, 2-3 mm. Stamens 10-14, unequal, longer ones 6-6.5(-10) mm. Ovary inferior. Styles 2, spreading to recurved, 1-2 mm in fruit. Capsule cupular to campanulate, 3-4.5 × 3.5-5 mm, apex truncate; persistent styles spreading to recurved. Seeds red-brown, fusiform, ellipsoid, or subglobose, 0.4-0.6 mm; wings 0.1-0.6 mm; seed coat striate veined. Fl. Jul-Aug, fr. Sep-Feb.
Dense to sparse forests or thickets in valleys, along stream banks, or on mountain slopes or tops; 700-2800 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan, SE Xizang, Yunnan, Zhejiang [Bangladesh, Bhutan, N India, Myanmar, Sikkim].