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, L. falcata and L. hybrida were separated using refined binary and continuous characters, whereas L. pentagonia, L. snogerupii and L. speculum-veneris were all mixed in a single cluster, as were L. castellana, L. falcata and L. scabra. In a further refined sampling, L. snogerupii was separated by PCA, DA and UPGMA, but L. pentagonia and L. speculum-veneris were still indistinguishable and formed a single mixed cluster. Based on the results, we propose to reduce L. castellana and L. scabra to synonyms of L. falcata, and L. skvortsovii to a synonym of L. hybrida, while subspecific rank is proposed for L. pentagonia as L. speculum-veneris subsp. pentagonia, comb. & stat. nov. A key and nomenclatural synopsis of accepted taxa is provided and their geographic distribution is outlined.
Citation: Wahlsteen E. & Tyler T. 2019: Morphometric analyses and species delimitation in Legousia (Campanulaceae). – Willdenowia 49: 21–33. doi: https://doi.org/10.3372/wi.49.49104
Version of record first published online on 25 March 2019 ahead of inclusion in April 2019 issue.