A Taxonomic Revision of Deutzia Thunb. (Hydrangeaceae) in Korea

A taxonomic revision of Deutzia in Korea was conducted based on critical observations of wild populations and herbarium specimens. Species delimitations were re-evaluated on the basis of morphological characters and distributions resulting in the recognition of five taxa. The texture of leaf, flower disk and capsules, the shape of leaf, inflorescence and capsules are useful diagnostic traits at the specific level. The five taxa are well distinguished from each other. Deutzia grandiflora var. baroniana can be distinguished by its distribution and calyx from Deutzia uniflora, which are morphologically similar. Deutzia paniculata Nakai, a rare and endemic plant, is characterized by having panicle in inflorescences. On the other hand, Deutzia glabrata Kom. is occasionally confused with Deutzia parviflora, but the most distinctive characters include the surface of leaves, the surface and size of capsules. Photographs and a key to five species of Deutzia were provided in addition to distribution.