[Spiraea prunifolia var. pseudoprunifolia (Hayata ex Nakai) Kitam., moreSpiraea prunifolia var. simpliciflora (Nakai) Nakai, Spiraea pseudoprunifolia Hayata ex Nakai, Spiraea simpliciflora (Nakai) Nakai]
Korea Flora: Deciduous shrub, 1.5-2m tall. Branchlets chestnut-brown, ridged, glossy. Leaves alternate, ovate to narrowly elliptic, acuminate apex, cuneate base, 2.5-4 × 1.5-2cm; margins finely serrate, glabrous on both surfaces. Petioles 2-3mm long. Flowers borne in umbellate inflorescences at the upper part of the plant, with 4-6(7) flowers per cluster on short lateral branches; pedicels 1.5cm long, glabrous. Calyx lobes 5, acuminate, sparsely pubescent. Petals white, 5, spatulate or elliptic, 4-6mm long. Ovaries 4-5; styles shorter than stamens, green; stamens yellow. Fruits follicles, glabrous.
Flowering: Mid-April to mid-May. Fruiting: Late August to early October. Distribution: Central to southern China; throughout Korea except South and Hamgyeongbukdo s. Taxonomic Remarks: Spiraea prunifolia is naturally distributed in mid to south of China and cultivated as an ornamental shrub both in Korea and in Japan. The double-flowered variant is treated as var. prunifolia, while single-flowered form is assigned to f. simpliciflora here. S. thunbergii is similar to S. prunifolia, differing primarly by its linear leaf blades and short pedicel (6-10mm vs 10-24mm of S. prunifolia).