XVI International Botanical Congess

The ancestral group or species is an important theoretical concept of phylogenetic systematics. A critical revision of the aggregate genus Gentiana s.l. in Ukraine, analysis of existing systems of this taxon, and our assessment of taxonomic significance of morphological, anatomical and palynological characters enabled us to propose morphogenetic series and to reconstruct hypothetic structural traits of the ancestral group. In all probabily, ancestors of Gentiana s.l. were herbaceous semirosette perennial plants with wide leaves and dense thyrsoid inflorescences composed by flowers with wheel-shaped corolla. The flowers were probably both anemo- and entomophilous. The fundamental type of shaft bundle in Gentiana s.l. is of the double threelacunar nodal type. We believe that the double unilacunar nodal pattern is of secondary origin.