Description from Flora of China
Spiraea silvestris Nakai.
Shrubs erect, 1–2 m tall. Branchlets red-brown or gray-brown, terete or slightly angled, pubescent when young, finally glabrous; buds ovoid, 1–2 mm, with several scales, glabrous, apex subobtuse. Petiole 2–5 mm, glabrous; leaf blade occasionally glaucescent abaxially, ovate or oblong-ovate to broadly lanceolate, 4–7 × 1–2 cm, membranous, glabrous or slightly puberulous on both surfaces, veins slightly raised abaxially, base subrounded or broadly cuneate, margin sharply serrate or doubly serrate, sometimes incised serrate, apex acute to acuminate. Corymbs terminal, compound, 4–6(–8) × 3–6 cm, many flowered; rachis and pedicels glabrous or pubescent; pedicels 6–10 mm; bracts linear, 2–3 mm. Flowers 6–7 mm in diam. Hypanthium campanulate or obconic, glabrous abaxially. Sepals triangular-ovate, 1.5–2 mm, spreading in fruit. Petals white, orbicular or obovate, (2–)3–4 × 2–3 mm, glabrous, base shortly clawed. Stamens 20–25, 2–3 × as long as petals. Disk annular, crenulate. Carpels fusiform, slightly tomentose; styles terminal, nearly equaling carpels, much shorter than stamens. Follicles 1.5–1.8 × 0.7–0.8 mm, slightly gray tomentose; styles recurved. Seeds linear. Fl. May–Jun, fr. Jul–Aug.
Three varieties occur in China; var. miyabei is native to Japan.
Mixed forests, mountain forests, slopes, gullies; 1000--2000 m. Anhui, Hubei, Shaanxi, Sichuan, Yunnan [Japan].