Search for a command to run...
Abstract In its current circumscription, Rubiaceae subfam. Rubioideae tribe Rubieae consists of 18 genera, i.e., Asperula , Callipeltis , Castrila , Crucianella , Cruciata , Cynanchica , Didymaea , Galium , Hexaphylla , Kelloggia , Mericarpaea , Microphysa , Phuopsis , Pseudogalium , Rubia , Sherardia , Thliphthisa and Valantia . It had long been recognized that the separation of Asperula with long corolla tubes from Galium with short corolla tubes is highly artificial, and indeed already the earliest molecular phylogenetic studies, confirmed by several studies since, could demonstrate the nonmonophyly of both Asperula and Galium . The combination of molecular phylogenetic studies based on several plastid DNA regions and partly also on nuclear ribosomal ITS and ETS, as well as sampling all genera of the tribe and all sections of Asperula and Galium , resulted in a widely resolved and well‐supported phylogenetic tree. The morphological homogeneity and distinctness of most of the clades identified allow us to propose a robust reclassification of Rubieae in which only monophyletic groups are recognized. In addition to the genera listed above (except for Castrila , which is included in Galium s.str.), we here recognize Cruciana stat. nov. (for Asperula sect. Cruciana ), Hydrogalium gen. nov. (for Asperula sect. Dioicae , A. sect. Glabella and Galium sect. Aparinoides ), Hamogalium gen. nov. (for Galium sect. Depauperata ), Jubogalium stat. nov. (for Galium sect. Jubogalium ), Altaiogalium gen. nov. (for Galium paniculatum ), and Trichogalium (for Galium sect. Platygalium ) as additional segregate genera of Asperula and Galium . These 23 genera fall into three subtribes, i.e., Kelloggiinae (containing Kelloggia ), Rubiinae (containing Didymaea and Rubia ) and Galiinae subtr. nov. (containing the remaining genera). An unsampled lineage of Galiinae, sometimes recognized as Leptunis , which may have to be recognized at generic rank, is briefly discussed. Brief descriptions of all genera are provided and altogether 293 new combinations of species are made.