The section Pseudophrys (Ophrys, Orchidaceae) in the Iberian Peninsula: a morphometric and molecular analysis

Abstract

Section Pseudophrys is a taxonomically critical species complex that has a history of circumscriptional uncertainty, suggesting the need for further evaluation. Its taxonomy in the Iberian Peninsula has been controversial, with treat- ments ranging from three species and three subspecies to ten species. Extensive observations in the field and anal- ysis of morphological characters based on 50 populations sampled show that most of the characters used by previous authors for distinguishing the species are variable among or even within populations. In the present study, repre- sentatives from the Iberian Peninsula and Morocco were investigated using morphometric and molecular (nuclear ribosomal ITS sequences) analyses. Seventeen floral characters and, in addition, four ratios, were measured from 642 live plants belonging to 50 populations of representatives of sect. Pseudophrys ( Ophrys arnoldii , O. bilunulata , O. dianica , O. fusca and O. lupercalis ). To determine characters distinguishing different species and to examine their circumscription, we performed morphometric analyses on three different subsets of sect. Pseudophrys , one with all the currently recognized species, another containing the closely related O. bilunulata and O. dianica , and finally the populations of O. arnoldii and O. lupercalis . These populations were treated as Operational Taxonomic Units (OTUs) and studied using cluster analysis, principal component analysis (PCA) and canonical discriminant analysis (CDA); box plots of selected quantitative characters were also made. Finally, variation in nrITS sequences among eight members of sect. Pseudophrys was analysed phylogenetically. Our results indicate that sect. Pseudophrys is mono- phyletic and well supported. We maintain the recognition of all taxa studied except O. arnoldii , and do not recognize any new taxa based on our examinations of the different populations of O. lupercalis . © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 359-375. ADDITIONAL KEYWORDS: ITS sequences - Portugal - Spain - taxonomy - variation gradient.