Spinella gen. nov. (Crassulaceae): A new genus segregated from Orostachys based on phylogenomic evidence

The genus Orostachys contains a single section (sect. Orostachys), which is subdivided into two subsections based on the presence or absence of spinose appendages at the leaf apex: subsect. Appendiculatae and subsect. Orostachys. Although numerous taxonomic studies have consistently raised questions regarding generic delimitation given that the two subsections do not form a monophyletic group, recent phylogenomic studies using complete chloroplast genome sequences and Angiosperms353 technology have provided strong evidence that these two subsections should be treated as separate genera. Therefore, in this study, we describe a new genus, Spinella H.-R. Lee & K.-S. Cheon, to accommodate taxa previously placed in Orostachys subsect. Appendiculatae. In accordance with the International Code of Nomenclature for algae, fungi, and plants (ICN), we present nine new nomenclatural combinations for taxa corresponding to this new genus and provide a key to distinguish Spinella from related genera.