A deciduous shrub up to 6 ft high, with arching branches; young shoots very hairy at first, becoming purple, nearly glabrous and very distinctly angled the second year; buds up to 1⁄6 in. long, brownish purple. Leaves oval, oblong or obovate, tapered at both ends, usually more abruptly so at the apex, mostly entire, sometimes three-toothed at the apex, 1⁄2 to 3⁄4 in. long, half as wide, silky all over. Flowers white, 1⁄3 in. in diameter, borne during June and July in corymbs about 1 in. across, terminating short leafy twigs that spring from the growths of the previous year; stamens twenty.
Native of W. Szechwan, China; discovered by Wilson in 1904; introduced in 1909. It is quite distinct from all other cultivated spiraeas in the combination of its silky leaves, and long, slender winter buds. The closely allied S. gemmata is distinguished ‘by its narrower, glabrous foliage, glabrous inflorescence and slenderer branches.’ (Pl. Wils., Vol. I (1913), p. 442).