Spiraea corymbosa Rafinesque. Phen: Jun-Aug; Aug-Oct. Hab: Rocky forests and woodlands, granitic domes, dry slopes of Piedmont monadnocks, rocky slopes in partial sun. Dist: A Southern and Central Appalachian endemic: sc. PA and w. MD south through w. VA, e. WV, to nw. NC, and perhaps also to e. TN (?), to n. AL(?), apparently fairly common only in w. VA. The species is limited to only a few counties each of NC and WV (Franklin 2004, Strausbaugh & Core 1978), and is not listed for TN in Chester, Wofford, & Kral (1997). Although Mohr (1901) listed the species for AL, it is not listed as a part of the state's woody flora by Clark (1971).
Origin/Endemic status: Endemic
Taxonomy Comments: Spiraea corymbosa is related to S. lucida Douglas ex Greene [= S. betulifolia var. lucida (Douglas ex Greene) C.L. Hitchcock] of the Rocky Mountains, S. betulifolia [= S. betulifolia var. betulifolia] of ne. Asia (Japan, e. Siberia, ne. China, Sakhalin, and the Kurile Islands), and S. aemiliana Schneider [= S. betulifolia var. aemiliana (Schneider) Koidzumi]. The group is often treated as 4 varieties or subspecies of S. betulifolia, but the morphological differences and strongly disjunct distribution warrant treatment as a relictual complex of related species; see Uttal (1974), Greene (1892), and others listed in Robertson (1974) for additional discussion and a range of conclusions.
Synonymy: = F, FNA9, K4, S, Va, WV; = Spiraea betulifolia Pall. ssp. corymbosa (Raf.) Taylor & MacBryde; = Spiraea betulifolia Pall. var. corymbosa (Raf.) Maxim. – C, G, K1, Pa, W, Robertson (1974); < Spiraea betulifolia Pall. – K3, RAB