Description from Flora of China
Spiraea sinobrahuica W. W. Smith; S. sinobrahuica var. aridicola W. W. Smith.
Shrubs 1–2 m tall. Branchlets suberect, slightly bent or distinctly tortuous, brownish to gray-brown, slender, gray-white tomentose when young, later glabrous; buds ovoid, small, softly hairy initially, apex obtuse. Petiole 2–5 mm, tomentose; leaf blade adaxially dark green, obovate or ovate to suborbicular, 1–2 × 0.5–1.5 cm, abaxially densely gray tomentose, adaxially pubescent, 3–5-veined at base, lateral veins prominent, base cuneate, margin ± obtusely serrate or doubly serrate, sometimes slightly 3-lobed, entire near base, apex obtuse. Umbels pedunculate, 1.5–3 × 2–3 cm, 5–25-flowered; pedicels 5–9 mm, densely yellow-white tomentose; bracts linear, 2–3 mm, yellow-white tomentose. Flowers 5–8 mm in diam. Hypanthium campanulate, tomentose abaxially. Sepals triangular, 1.5–2 × 1–1.5 mm, erect in fruit, apex acute or shortly acuminate. Petals white, broadly obovate or suborbicular, 3–4 × 2.5–3.5 mm, glabrous, base shortly clawed, apex emarginate or obtuse. Stamens ca. 20, ca. 1/2 as long as petals. Disk annular, almost divided into 10 emarginate lobes. Carpels gray-white pubescent; styles shorter than stamens. Follicles spreading, sparsely pubescent; styles abaxial, somewhat divergent. Fl. Apr–Jul, fr. Jul–Oct.
Plants with branchlets distinctly tortuous, leaf blades broadly ovate to suborbicular, 0.5–1 cm wide, and umbels 5–12-flowered are Spiraea yunnanensis f. tortuosa (Rehder) Rehder (J. Arnold Arbor. 14: 205. 1933; S. tortuosa Rehder in Sargent, Pl. Wilson. 1: 445. 1913). The typical form has branchlets slightly bent, leaf blades obovate or ovate, 0.8–1.5 cm wide, and umbels 8–25-flowered.
Dry thickets, mountain valleys, slopes, rocks along gullies, roadsides; 1300--2800 m. W Sichuan, Yunnan.