A taxonomic revision of the genus Sorbaria (Rosaceae) with a new infrageneric classification based on morphology, micromorphology, and palynology

In the present study, we presented a taxonomic revision of the genus Sorbaria (Sorbarieae; Amygdaloideae) with a new infrageneric classification. Moreover, we extensively reviewed various data for Sorbaria species, including previous anatomical, micromorphological, and palynological data. The new sectional classification was based on morphological, micromorphological, and palynological evidence, with two sections: sect. Sorbaria aut. and sect. Kirilowiana J.-H. Song & S.-P. Hong (sect. nov.). Overall, four species and five varieties (including two nomenclatural novelties) were recognized: S. sorbifolia (Linnaeus) A. Braun var. sorbifolia, S. sorbifolia var. glandulifolia J.-H. Song & S.-P. Hong, S. sorbifolia var. stellipila Maximowicz, S. pallasii (G. Don) Pojarkova, S. tomentosa (Lindley) Rehder var. tomentosa, S. tomentosa var. angustifolia (Wenzig) Rahn., S. kirilowii (Regel & Tiling) Maximowicz var. kirilowii, S. kirilowii var. arborea (C.K. Schneider) J.-H. Song & S.-P. Hong (comb. & stat. nov.), and S. kirilowii var. dubia (C.K. Schneider) J.-H. Song & S.-P. Hong (comb. nov.). Some illustrations and syntype were designated as the lectotype for several names. The classification was based on a comprehensive morphological examination of herbarium specimens, including field observations and observations of types, micromorphological, and palynological characteristics. In addition, we provided an identification key, diagnostic characteristics, full descriptions, comprehensive nomenclatural treatments and taxonomic notes (including complete synonymy), and distribution maps of Sorbaria species.