Diversification of New World Cleomaceae with emphasis on Tarenaya and the description of Iltisiella, a new genus

Abstract The family Cleomaceae is represented in the Neotropics by nine native lineages, with some of them currently recognized as distinct genera and others in need of clear delimitation. We present here a new phylogenetic hypothesis for the New World Cleomaceae with a more comprehensive sampling, including samples of 62 species with emphasis on Tarenaya and based on nrDNA ITS and cpDNA matK and ndhF . Six clades are supported: (1) a new clade comprising Cleome tenuis and Physostemon humilis ; and five other previously identified clades: (2) the Dactylaena clade, including the monophyletic Dactylaena and the paraphyletic Physostemon and Mitostylis ; (3) the Andean clade, comprising Andinocleome and Podandrogyne ; (4) the Melidiscus clade; (5) the Cleoserrata clade, and (6) the Tarenaya clade; the last three corresponding to genera with the same name. The lineage comprising C . tenuis and P . humilis is strongly supported by morphological and molecular datasets, and a new genus, named Iltisiella , comprising these species is proposed here. Tarenaya is clearly demonstrated to be a monophyletic genus, corroborating previous analyses. We identify four subclades in its topology, and the relationships among the species in each subclade revealed to be moderately to strongly resolved. Furthermore, we conducted a historical biogeographical analysis of the New World Cleomaceae on time‐calibrated trees, and our results suggest an Oligocene origin at least 35.02 Mya with a MRCA distributed in Mesoamerica and the Northern Andes. For Tarenaya , our results suggest a Miocene origin at least 17 Mya, with the most recent common ancestor in the Chacoan and Atlantic Forest geographic areas.