2018): Distributions of vascular plants in the Czech Republic. Part 7. -Preslia 90: 425-531.The seventh part of the series on the distributions of vascular plants in the Czech Republic includes grid maps of 104 taxa in the genera Anthriscus, These maps were produced by taxonomic experts based on examined herbarium specimens, literature and field records. Many of the studied native species are on the national Red List. The genus most affected by decline in abundance is Gentianella, which includes six taxa extirpated from this country and six taxa critically threatened. Another group with a high proportion of endangered species comprises aquatic and wetland plants, which are represented by Callitriche hermaphroditica, Hydrocharis morsusranae, Najas minor, Pseudognaphalium luteoalbum and Stratiotes aloides. Other ecologically specialized groups include mainly montane wetland plants (Epilobium anagallidifolium, E. nutans and Rubus chamaemorus) and plants of rocky habitats (Polypodium interjectum, Trichomanes speciosum and Woodsia ilvensis). The previously rare Woodsia alpina has been extirpated from this country. Alien species mapped in this paper include both archaeophytes and neophytes, mainly from the genera Anthriscus, Cochlearia, Elodea, Epilobium, Hordeum and Phleum. Cochlearia danica, Dittrichia graveolens and Limonium gmelinii have recently colonized habitats along the roads treated by de-icing salt. Senecio inaequidens has also spread mainly along motorways. Epilobium adenocaulon is another successful neophyte; it is now widespread throughout this country and the most successful hybrid parent within the genus. Neophyte aquatics are represented by Egeria densa, Elodea canadensis and E. nuttallii. Spatial distributions and often also temporal dynamics of individual taxa are shown in maps and documented by records included in the Pladias database and available in electronic appendices. The maps are accompanied by comments that include additional information on the distribution, habitats, taxonomy and biology of the taxa. K e y w o r d s:

Ranunculus section Batrachium (water crowfoot) ranks among the most taxonomically challenging aquatic plant groups due to morphological reduction, phenotypic plasticity, polyploidy and reticulate evolution. This study, for the first time in this group, linked morphology, genome size and genetic data (two non-coding regions of plastid DNA and the ITS region of nuclear ribosomal DNA). This extensive data set, including 258 central European populations, enables us to recognize widespread lineages from hybrids and to trace the evolutionary processes underlying the observed diversity. Most of the traditionally recognized species are supported. However, the presence of two morphologically cryptic but genetically well-differentiated lineages was detected within Ranunculus trichophyllus, and three separate lineages of different parentage were confirmed in the Ranunculus penicillatus complex. An allopolyploid origin was revealed in Ranunculus aquatilis, Ranunculus baudotii and in both lineages of R. trichophyllus, for which the parentage has not yet been studied, and allopolyploidy is suspected in all other polyploid taxa except for the triploid cytotype of Ranunculus fluitans, which is most likely autopolyploid. We detected putative F1 hybrids of seven different parentage combinations, including two involving Ranunculus rionii, representing the first known hybrids of this species. An additional 13 hybrid cytotypes (backcrosses or entailing additional polyploidization) were revealed; c. 20% of Ranunculus peltatus accessions seem to be influenced by introgression detectable only using sequence data. The Batrachium group is remarkable due to the coexistence of well-defined lineages with recently evolved biotypes arising due to hybridization and polyploidization.

Despite their complex evolutionary histories, aquatic plants are highly underrepresented in contemporary biosystematic studies. Of them, the genus Callitriche is particularly interesting because of such evolutionary features as wide variation in chromosome numbers and pollination systems. However, taxonomic difficulties have prevented broader investigation of this genus. In this study we applied flow cytometry to Callitriche for the first time in order to gain an insight into evolutionary processes and genome size differentiation in the genus. Flow cytometry complemented by confirmation of chromosome counts was applied to an extensive dataset of 1077 Callitriche individuals from 495 localities in 11 European countries and the USA. Genome size was determined for 12 taxa. The results suggest that many important processes have interacted in the evolution of the genus, including polyploidization and hybridization. Incongruence between genome size and ploidy level, intraspecific variation in genome size, formation of autotriploid and hybridization between species with different pollination systems were also detected. Hybridization takes place particularly in the diploid – tetraploid complex C. cophocarpa – C. platycarpa, for which the triploid hybrids were frequently recorded in the area of co-occurrence of its parents. A hitherto unknown hybrid (probably C. hamulata × C. cophocarpa) with a unique chromosome number was discovered in the Czech Republic. However, hybridization occurs very rarely among most of the studied species. The main ecological preferences were also compared among the taxa collected. Although Callitriche taxa often grow in mixed populations, the ecological preferences of individual species are distinctly different in some cases. Anyway, flow cytometry is a very efficient method for taxonomic delimitation, determination and investigation of Callitriche species, and is even able to distinguish homoploid taxa and identify introduced species.

Cytotype variation, cryptic diversity and hybridization in Ranunculus sect. Batrachium revealed by flow cytometry and chromosome numbers Cytotypová variabilita, kryptická diverzita a hybridizace u lakušníků (Ranunculus sect. Batrachium) odhalená pomocí cytometrických a karyologických analýz Jan P r a n č l 1,2 , Petr K o u t e c k ý 3 , Pavel T r á v n í č e k 1 , Vlasta J a r o l í m o v á 1 , Magdalena L u č a n o v á 1,3 , Eva K o u t e c k á 3 & Zdeněk K a p l a n 1,2

The sixth part of the series on the distributions of vascular plants in the Czech Republic includes grid maps of 112 taxa in the genera Athyrium,

The eighth part of the series on the distributions of vascular plants in the Czech Republic includes grid maps of 106 taxa in the genera Abutilon,

The fifth part of the series on the distributions of vascular plants in the Czech Republic includes grid maps of 106 taxa of the genera Arnica,

No abstract