Taxonomic review of Spiraea chartacea compared with its related species of section Chamaedryon in Korea

A taxonomic revision of Korean endemic Spiraea chartacea is presented compared with its related three species, S. blumei, S. turczaninowii (≡ S. pubescens Turcz.), and S. chinensis, of section Chamaedryon in Korea. Species delimitations are re-evaluated based on critical observations of wild populations and extensive herbarium material. The shape of leaf, the type and distribution of trichome in stem, leaf, peduncle, pedicel, hypanthium, sepal, carpel, and follicle are useful diagnostic traits at the specific level. Almost all morphological and leaf anatomical observations of S. chartacea belong within the range of S. turczaninowii. Therefore, S. turczaninowii is placed into synonymy of S. chartacea by priority. Photographs and a key to three species of Spiraea section Chamaedryon are provided in addition to complete descriptions including information on nomenclatural types, synonymies, chromosome numbers, distributions, and specimens examined.