52. Spiraea myrtilloides Rehder in Sargent, Pl. Wilson. 1: 140. 1913.
细枝绣线菊 xi zhi xiu xian ju
Shrubs 2–3 m tall, much branched. Branchlets red-brown to dark brown, angled, sparsely villous or subglabrous; buds ovoid, 3–4 mm, with several brown scales, glabrous or subglabrous, apex acute. Petiole 1–2 mm, glabrous or subglabrous; leaf blade abaxially greenish, ovate to ovate-oblong or obovate-oblong, 6–15 × 4–7 mm, abaxially sparsely pubescent or glabrous, adaxially glabrous, inconspicuously pinnately veined, prominently 3-veined basally, base cuneate, margin entire or with ca. 3 obtuse teeth near apex, apex obtuse, rarely acute. Racemes umbellate, 2–4 × 2–3.5 cm, 7–20- or more flowered; rachis and pedicels glabrous or sparsely pubescent; pedicels 3–8 mm; bracts linear or lanceolate, 2–3 mm, glabrous. Flowers 5–6 mm in diam. Hypanthium campanulate, glabrous or subglabrous abaxially. Sepals triangular, 1–1.5 mm, erect or spreading in fruit, apex acute. Petals white, suborbicular, 2–3 mm, about as broad as long, glabrous, base shortly clawed, apex obtuse. Stamens ca. 20, equaling petals. Disk annular, 10-lobed. Carpels puberulous; styles shorter than stamens. Follicles straightly spreading, glabrous, puberulous only on adaxial suture, or densely pubescent throughout; styles terminal, divergent. Fl. Jun–Jul, fr. Aug–Sep.
Mixed forests, open forests, valleys, slopes, shady places; 1500--3100 m. Gansu, Henan, Hubei, Jiangxi, Qinghai, Shaanxi, Sichuan, Xizang, Yunnan.