Phylogenetic Analysis of Meconopsis (papaveraceae) and Evaluation of Two Controversial Taxonomic Species

Meconopsis is a genus native to the high elevation habitats that range from the western Himalaya eastward to the Hengduan Mountains (China). The genus has been the subject of several taxonomic treatments and monographs by generations of botanists, which has led to a long and confusing taxonomic history with inconsistent species concepts and conflicting interpretations of relationships among named taxa. In the present study, we reconstructed the evolutionary history of Meconopsis utilizing four chloroplast markers (rbcL, matK, ndhF and the trnL-trnF intergenic spacer) and the nuclear ribosomal internal transcribed spacer (nrITS). Incongruence found between the cpDNA and nrITS trees was investigated to detect reticulate evolution, using the approximately unbiased (AU) method. Based on the evolutionary patterns revealed by our resultant phylogenies, we evaluated the species delimitations of the two most controversial “species” (Meconopsis horridula and Meconopsis napaulensis) in the genus and the inconsistency among their previously published treatments. As a result, we provide taxonomic suggestions for these species that include the proposal of a M. horridula species complex.