Spiraea arcuata Hook. fil.

Shrubs small. Branches arched, dark brown, shining, stout, slightly angled, deeply grooved, glabrous when old; buds long ovoid, with 2 scales. Petiole short, slender, glabrous or subglabrous; leaf blade long elliptic to obovate, 8–12 × 3–5 mm, glabrous or subglabrous on both surfaces, base cuneate, margin entire or obtusely 3–8-serrate or lobed apically, apex obtuse, rarely subacute. Corymbs terminal on short, lateral branchlets, compound, dense, many flowered; rachis and pedicels puberulous; pedicels short. Flowers 6–8 mm in diam. Hypanthium turbinate, pubescent abaxially. Sepals triangular, reflexed in fruit, apex usually acute. Petals pink, suborbicular, glabrous. Stamens slightly shorter than or subequalings petals. Disk annular, broadly crenate. Follicles spreading, wholly exserted, shining, glabrous, rarely puberulous only on adaxial suture; styles terminal on abaxial side, divergent. Fl. May–Jul, fr. Aug–Sep.

Himalaya (Garhwal to Bhutan), Tibet, N. Burma, W. China.

Xizang, Yunnan [Bhutan, India, N Myanmar, Nepal, Sikkim].

3500-4900 m

Forests, thickets on river banks, river valleys, subalpine rocky places; 3000--4200 m.

Spiraea canescens D. Don var. glabra J. D. Hooker & Thomson.