(Crassulaceae), a new species from Mt. Daeam in Korea.

individuals from Mt. Daeam, once referred to as , exhibit certain morphological characters that are unique within the genus. is one of the most notorious groups for taxonomic problems due to the high morphological variation found in leaf shape, stem numbers, phyllotaxis and seed structure. Taxa in also easily hybridize, further leading to taxonomic confusion. To carefully confirm the identity of the putative new species from Mt. Daeam, we examined morphological characters from ~100 herbarium sheets of six closely related species. A molecular phylogenetic approach was also employed to delimit the species boundary and infer the phylogenetic relationships among the seven species, including the species from Mt. Daeam. Both morphological and molecular phylogenetic results indicated that the species found on Mt. Daeam is a new species that is more closely related to and than to the remaining four species. Here, we provided a full description of the new species as well as an updated key for the seven species examined.