Coreopsis (Asteraceae) sect. Pseudoagarista is the largest section in the genus. It is disjunct between the high mountains of Mexico and high elevations in the Andes. Most species in the section are similar in floral and fruit characters, and aredistinguished primarily by leaf characters. Despite the morphological similarity among all species, the monophyly of the sectionhas been called into question by molecular data. Prior studies of tribe Coreopsideae have been equivocal with, cpDNA markersindicating monophyly but nrDNA ITS sequences have not resolved the section as monophyletic. Expanded cpDNA and nrDNAITS datasets, and statistical (i.e., AU) tests of the ITS and cpDNA topologies provide support that sect. Pseudoagarista is notmonophyletic. Both data partitions strongly support the Mexican and South American subclades as monophyletic. The lowcpDNA sequence variation within each subcl...