Duan, Lei, Harris, AJ, Ye, Wen, Deng, Shuang‐Wen, Song, Zhu‐Qiu, Chen, Hong‐Feng, and Wen, Jun
The Cladrastisclade is an early‐diverged lineage within the subfamily Papilionoideae of Leguminosae. Several taxonomic uncertainties limit a robust understanding of its taxonomy: (1) Should the genus Platyosprionbe resurrected? (2) How should Cladrastisbe delimited to maintain the generic monophyly? (3) Is Styphnolobiumbest classified into two or three sections? We assessed specific/sectional/generic boundaries within this clade by integrating evidence from phylogenetic analyses, morphology, and multivariate ecological methods. With an extensive sampling of the clade, we reconstructed the phylogenies using nrDNA (ITS) and plastid DNA regions (matK, psbA‐trnH, trnL‐F). Based on environmental data for 841 occurrences, clusters of species were sought according to their environmental preferences with the principal component analysis (PCA), and explicit hypotheses on species/sectional boundaries were tested using ecological niche modeling (ENM). A new tribe, Cladrastideae, is established based on the Cladrastisclade with four monophyletic groups: the Cladrastis platycarpacomplex, Cladrastiss.str., Pickeringiaand Styphnolobium. The C. platycarpacomplex constitutes the resurrected genus Platyosprion. The putative species C. chingii, C. parvifolia, C. scandensand C. yungchuniiare suggested to be treated as synonyms of Platyosprion platycarpum. Cladrastisis recircumscribed as equal to Cladrastiss.str., with three species from eastern Asia, and one species, C. kentukea, from eastern North America. Styphnolobiumis herein classified into three sections: St. sect. Oresbios, St. sect. Styphnolobiumand a new section, St. sect. Affine.