Taraxacum mariae J. Marciniuk & P. Marciniuk is a new triploid species of T. sect. Palustria. In terms of morphology it is closest to the group of T. brandenburgicum and T. bibulum. In the presented paper, the description of the new species, its distribution, diagnostic characters and habitat requirements are provided.

The genus Taraxacum is taxonomically complicated due to apomixis. Therefore, there are significant differences in knowledge of regional Taraxacum-Floras among European countries. Similarly, some taxa are well characterised with well-known distribution, whereas some ones are known e.g. from a single locality. Taraxacum scanicum of section Erythrosperma is one of the most common microspecies of this section in Europe. Recently, this taxon was split into three microspecies. In this study we map the distribution of three described taxa of this group in Poland, i.e. T. scanicum s.s., T. prunicolor and T. cristatum. The survey showed that T. scanicum has a similar distribution as T. prunicolor in Poland. This is in contrast with the hitherto known distribution of both taxa. T. cristatum was found at a single locality that is quite distant from the distribution in southern central Europe. We also provide with new morphological characteristics of achenes and pollen for T. scanicum s.s. and T. prunicolor.

This paper presents the results of research on nuclear DNA polymorphism in six apomictic species of marsh dandelions (Taraxacum sect. Palustria): Taraxacum bavaricum, T. belorussicum, T. brandenburgicum, T. paucilobum, T. subdolum and T. vindobonense. The studies demonstrated the existence of clear genetic differences between species and the existence of nuclear DNA polymorphism within each of the studied species.

The paper presents new records of 24 vascular plant species from 11 Eurasian countries. One taxon (Orobanche laxissima) is reported from Armenia; one (Epipactis condensata) from Azerbaijan; two (Phragmites americanus, Polygala multicaulis) from Belarus; one (Stipa caucasica) from Egypt; one (Puccinellia hauptiana) from Kyrgyzstan; three (Aquilegia xinjiangensis, Geranium saxatile, Ranunculus songaricus) from Mongolia; one (Stipa roborowskyi) from Pakistan; three (Echinochloa muricata, Erigeron acris subsp. podolicus, Hypericum majus) from Poland; six from Russia, whereof one (Zanthoxylum armatum) from the European part of Russia and five (Chaerophyllum aureum, Elsholtzia densa, Poa compressa, Ranunculus subrigidus, Viola sororia) from the Asian part of Russia; two (Ludwigia repens, Sagittaria latifolia) from Slovakia; and three (Rubus ambrosius, Rubus camptostachys, Rubus perrobustus) from Ukraine. For each species, synonyms, general distribution, habitat preferences, taxonomy with remarks on recognition and differentiation of the species from the most similar taxa occurring in a given country, as well as a list of recorded localities (often far from the previously known areas), are presented.

This study represents the first report on the embryological characteristics of triploid male-sterile dandelion Taraxacum belorussicum (section Palustria) from Poland. While this taxon is considered to be a male-sterile species, we found that the investigated individuals produced pollen. Irregular tetrads, triads and diads with microspores of unequal size were observed in the pollen loculi as a result of disturbed meiotic division, while anthers’ tapetum did not show structural disorders. Possible reasons for the plasticity in the expression of male sterility, as well as the role of pollen in apomicts, are discussed. Flowers of the examined individuals contained well-developed nectaries. The course of embryological processes in the ovules indicated an apomictic mode of reproduction in T. belorussicum. We observed meiotic diplospory of the Taraxacum type, in which first meiotic division starts but results in nuclear restitution, while undisturbed second meiotic division gives rise to a dyad of unreduced megaspores (diplodyad). After three mitotic divisions of the chalazal megaspore, a seven-celled unreduced female gametophyte developed. The features of ovule anatomy and characteristics of a mature female gametophyte corresponded to these described in sexually reproducing dandelions.