Description from Flora of China
Exochorda racemosa (Lindley) Rehder subsp. serratifolia (S. Moore) F. Y. Gao & Maesen.
Shrubs to 2 m tall. Branchlets red-purple when young, later dark purple; buds purple-red, ovoid, apex obtuse. Petiole 1–2 cm, glabrous; leaf blade elliptic to oblong-ovate, 5–9 × 3–5 cm, slightly pubescent when young, later glabrous, base cuneate or broadly so, margin entire below middle, serrate above middle, apex obtuse or acute. Raceme 3–4 cm, 4–7-flowered; peduncle and pedicels glabrous; bracts linear-lanceolate, ca. 3 mm, glabrous. Flowers 3–4 cm in diam.; pedicel 2–3 mm. Hypanthium shallowly campanulate, glabrous. Sepals triangular, ca. 2 mm, glabrous, apex acute. Petals oblong to obovate, ca. 1.5 × 1 cm, base long clawed, apex emarginate. Stamens ca. 25, 2–4-fascicled. Capsule glabrous; fruiting pedicel 2–3 mm. Fl. May–Jun, fr. Jul–Aug.
Exochorda serratifolia var. polytricha C. S. Zhu (Acta Phytotax. Sin. 32: 432. 1994), described from N Henan (Jiyuan Xian), was said to differ in having the current year’s branchlets, petioles, leaf blades abaxially, inflorescence rachis, and pedicels all densely white crispate pubescent.
Scrub, slopes, river sides. NE Hebei (Wuling Shan), Liaoning (Qian Shan) [Korea].