Description from Flora of China
Hydrangea aspera D. Don subsp. sargentiana (Rehder) E. M. McClintock.
Shrubs 2-3 m tall. Branchlets, petioles, and peduncles with dense, purple, semitranslucent, long, apically forked and acute hairs. Branchlets thick. Petiole thick, 3-9 cm; leaf blade abaxially gray-green to slightly purple when fresh, adaxially dark green, elliptic, oblong-ovate, or broadly ovate, 9-30 × 6-16 cm, submembranous to thinly papery, abaxially densely slightly curved villous, adaxially densely translucent strigose, secondary veins 8-11 on both sides of midvein, abaxially prominent, base rounded to shallowly cordate, margin irregularly triangular dentate to denticulate, apex acuminate. Inflorescences corymbose cymes, 10-16 cm wide, apex arcuate; branches numerous, crowded together at apex of peduncle. Sterile flowers with sepals 4, white, obovate-orbicular to broadly orbicular, 0.9-1.4 × 0.8-1.7 cm in fruit, margin entire. Fertile flowers with calyx tube campanulate, ca. 1 mm; teeth triangular, ca. 0.5 mm. Petals purplish blue, ovate, ca. 2 mm. Stamens unequal, some of shorter ones equaling petals, longer ones ca. 4 mm. Ovary inferior. Styles 2, ca. 1.5 mm in fruit; stigmas capitate, small. Capsule hemispheric, 3-4 mm in diam., apex truncate. Seeds brown, ellipsoid, slightly compressed, winged at both ends; seed coat striate veined. Fl. Jul, fr. Sep.
* Dense forests in valleys or on mountain slopes; 700-1800 m. W Hubei.