Leaf width, nrDNA and cpDNA its sequence variation within central European Bulbocodium vernum and B. versicolor...

The taxonomy of the genus Bulbocodium, in which two European species, a smaller eastern (B. versicolor) and a more robust western (B. vernum) are included, has been controversial since the description of the eastern species in 1821. Nuclear encoded ribosomal DNA ITS1 and the entire chloroplast DNA ITS were sequenced from several European populations, from France to the Ukraine, and the leaf width of mature living individuals was measured and analysed by ANOVA and Tukey-test. Although the studied DNA regions proved to be invariable, leaf width shows extreme variability. We found no correlation between the leaf size of the individuals and the geographical position of the populations, and in addition, the sequenced DNA regions showed total uniformity. Thus, our results do not support the division of the genus Bulbocodium into two taxa, at least in the sampled area. The formerly described size variants can be treated taxonomically at the forma level.