Shrub 1.2 - 3 m tall, 1.8 - 2.4 m wide Leaves: alternate, short-stalked, shiny dark green, 2 - 5 cm long, 1.3 - 1.9 cm wide, egg-shaped or elliptic to elliptic-oblong, tapering to both ends, toothed, hairless or finely hairy beneath. Fall color is yellowish orange to purplish bronze, but not spectacular. Flowers: borne three to six in an unbranched umbel arising from the leaf axil, white, 8 - 10 mm in diameter, with five sepals, five petals (often double, where stamens and pistils are replaced with petals), and stamens shorter than the petals. Fruit: firm and dry, breaking open along one side (follicle), spreading, hairless, with tiny oblong seeds. Twigs: slender, zigzag, shiny brown, hairy to nearly hairless.
Similar species: Spiraea alba, Spiraea x billiardii, and Spiraea tomentosa all have branched inflorescences, making them easy to distinguish from this species.
Flowering: May to June
Habitat and ecology: This species was introduced from Eurasia and rarely escapes cultivation. Only one voucher was collected in the Chicago Region, growing in a forest preserve near an old homesite.
Occurence in the Chicago region: non-native
Etymology: Spiraea comes from the Greek word speiraira, a plant used to make garlands. Prunifolia means "with leaves like a plum."
Shrub 2-3 m; lvs ovate or ovate-oblong, short-petioled, 2-4 cm, finely serrulate; umbels axillary, sessile or nearly so, with 3-6 white, commonly double fls 8-10 mm wide on pubescent pedicels 1-2 cm. Native of e. Asia, often escaped in our range. May.
Two other cult. spp. and one hybrid that would key to S. prunifolia occasionally escape. S. thunbergii Siebold has lance-linear, sparsely serrate lvs and sessile or subsessile umbels with 3-6 fls on glabrous pedicels 1-1.5 cm. S. chamaedryfolia L. has ovate or ovate-oblong lvs with numerous sharp teeth, and peduncled dense corymbs of fls with exserted stamens, terminating leafy branches. S. ضanhouttei (Briot) Zabel, the Bridal wreath, has rhombic-ovate to obovate lvs few-toothed above, and peduncled corymbs of fls with short stamens, terminating short leafy branches.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.