Morphometric analyses and species delimitation in legousia (Campanulaceae)

Abstract

In order to evaluate the traditional morphological characters commonly used to distinguish the taxonomically problematic species of Legousia, we carried out a morphometric study with univariate analysis, principal component analysis (PCA), discriminant analysis (DA) and cluster analysis (UPGMA). The analyses were based on data from 436 individuals on 207 herbarium specimens from 18 countries in Europe, Africa and Asia representing all recently accepted species of the genus. Legousia falcata was found clearly distinct based on binary characters, Lfalcata and Lhybrida were separated using refined binary and continuous characters, whereas Lpentagonia, Lsnogerupii and Lspeculum-veneris were all mixed in a single cluster, as were Lcastellana, Lfalcata and LscabraIn a further refined sampling, Lsnogerupii was separated by PCA, DA and UPGMA, but Lpentagonia and Lspeculum-veneris were still indistinguishable and formed a single mixed clusterBased on the results, we propose to reduce Lcastellana and Lscabra to synonyms of Lfalcata, and Lskvortsovii to a synonym of Lhybrida, while subspecific rank is proposed for Lpentagonia as Lspeculum-veneris subsppentagonia, comb& statnov. A key and nomenclatural synopsis of accepted taxa is provided and their geographic distribution is outlined.