Morphological variation within the Edraianthus graminifolius complex (Campanulaceae) from the central Balkan Peninsula – evidence from multivariate statistical analysis

Abstract

The Edraianthus graminifolius complex is one of the most interesting groups within the genus Edraianthus DC (Campanulaceae). The plants inhabit a variety of habitats and there is a micro-geographic and ecological differentiation of populations, accompanied by pronounced morphological variation. Hence, it is not surprising that this complex is taxonomically a very controversial group. On the one hand it is described to comprise only two to four taxa, including subspecies, and on the other, a classification comprising 23 taxa of the rank of species and subspecies has been proposed.

The basic aim of the present study therefore was to quantify the morphological and anatomical differences within and between populations of this complex from the central and western parts of the Balkan Peninsula (Serbia, Montenegro, Bosnia and Herzegovina, and Croatia), and to determine whether there are, in fact, clear morphological differences between these populations.

For these purposes, several multivariate statistical analyses (PCA – principal component analysis, CDA – canonical discriminant analysis, clustering UPGMA analysis based on Mahalanobis distances, and CA – correspondence analysis) of vegetative and generative plant organs have been carried out. The morpho-anatomical analysis of 704 individuals from 44 populations has confirmed that there are several morphologically distinct groups of populations in the central Balkans, between which no strict morphological discrimination exists. Some of these distinct groups of populations correspond to taxa E. caricinus Schott, Nyman, & Kotschy, E. montenegrinus Horak, E. jugoslavicus Lakušić and E. vesovicii R. Lakušić, while others were identified for the first time in this study.