Phylogeny of subtribe Gonolobinae (Apocynaceae‐Asclepiadoideae) based on molecular and morphological data with a revised generic classification

Abstract The presently most densely sampled molecular phylogeny of the widespread New World subtribe Gonolobinae is presented, including about 35% of the ca. 520 species. Sampling focused on an even representation of the three main areas of total Gonolobinae distribution, South America, Central/North America, and the West Indian Islands, and the inclusion of as many of the mono‐ and bitypic genera as possible. Both Bayesian and maximum likelihood analyses of cpDNA and ITS roughly place the taxa in five clades, one exclusively composed of West Indian Island taxa, three of Central and North American taxa, and one including all South American taxa, but also including taxa from all American regions. A monophyletic Matelea would either subsume all Gonolobinae under this genus, including well‐known and easily recognized genera such as Fischeria , Gonolobus and Macroscepis , or be restricted to a clade of South American plants mostly in wet and riparian transitional forests. To reconcile the phylogenetic structure of the subtribe and classification, the ongoing process of resurrecting genera recognized by early botanists (e.g., Acomosperma , Callaeolepium , Himantostemma , Lhotzkyella , Poicilla , Poicillopsis ) is continued and five genera need to be described as new ( Pauciflora , Portoricana , Potamoampelos , Weigendia [including its type, Weigendia cajamarcana sp. nov.], Yucatania ). Furthermore, 25 new combinations at species level are proposed, and 13 lectotypes and 1 second‐step lectotype are designated. A total of 50 genera is recognized in Gonolobinae, and a morphological description is given for each genus. One genus, Stelmagonum , is excluded from Gonolobinae. Keys are provided for the three main geographical areas, South America, West Indian Islands, and Central and North America.