A detailed study of Taraxacum sect. Ruderalia for the 8th volume of the Flora of the Czech Republic revealed five new agamospermous species, viz. T. atroviride Štěpánek et Trávníček, T. clarum Kirschner, Štěpánek et Trávníček, T. moldavicum Chán, H. Ollgaard, Štěpánek, Trávníček et Žíla, T. urbicola Kirschner, Štěpánek et Trávníček and T. violaceifrons Trávníček. These species are formally described, thoroughly characterized morphologically and compared with similar taxa. They are known from numerous localities in Central Europe; T. moldavicum, in addition to the Central European distribution, is known to occur in two regions in Denmark. All these species are also documented by photographs of their general habit and important features.
Two new species, Taraxacum maricum and Taraxacum cristatum, of the section Erythrosperma from Central Europe are described in this paper. These species are similar to western European taxa, T. maricum to T. proximum, and T. cristatum is morphologically close to T. scanicum. Both new taxa are triploid apomictic microspecies. Specific characteristics, information on distribution and ecology and comparison with similar species are presented. Pictures and distribution maps of the new species are also included.