Differentiation of the taxa of the genus Taraxacum sect. Erythrosperma on the basis of morphological characters on achenes and outer bracts

摘要

The genus Taraxacum sect. Erythrosperma is represented by one diploid species and several triploid microspecies in the territory of Slovakia. In comparison with the sect. Ruderalia it is not widespread and its occurrence is limited to areas with xerophilous and thermophilous vegetation. Besides some morphological characters on leaves particular microspecies within the section Erythrosperma differ by position and size of outer bracts as well as size and colour of achenes. Morphometric analyses with employment of multivariate statistic methods in the sample of 745 achenes and 447 outer bracts showed no substantial differences in the studied characters between diploid Taraxacum erythrospermum and triploids (T. cristatum, T. danubium, T. prunicolor). Inthe case of analysis of sole triploid microspecies, these microspecies can be distinguished from each other on the basis of characters on achenes and outer bracts quite well. These characters, when combined with other morphological characters, can playan important role in determination of particular taxa.