Distributions of vascular plants in the Czech Republic. Part 11.

The eleventh part of the series on the distributions of vascular plants in the Czech Republic includes grid maps of 85 taxa in the genera Agrostemma, Berula, Bromus, Carex, Corydalis, Echinocystis, Festuca, Himantoglossum, Lychnis, Ophrys, Ornithopus, Pseudofumaria, Quercus, Salix, Sium and Vaccaria. These maps were produced by taxonomic experts based on examined herbarium specimens, literature and field records. Most of the studied species are on the national Red List. Agrostemma githago, previously a noxious weed in cereal fields throughout this country, has virtually been eliminated from arable land and is now only rarely recorded in ruderal habitats. The recently described Festuca albensis is a species endemic to three sandy areas in Germany and the Czech Republic. It is threatened due to its restricted distribution, hybridization and habitat eutrophication. In contrast to the majority of orchids, Ophrys apifera has expanded its range and colonized secondary habitats in central Europe. In the Czech Republic it was for the first time recorded in 1980. However, in spite of the increase in the number of records, most of the populations are small. Himantoglossum calcaratum subsp. rumelicum and Salix starkeana have been extirpated from this country and are classified as nationally extinct. Vaccaria hispanica has not been observed for more than three decades and is classified as missing. Besides numerous archaeophytes and neophytes, mainly of the genus Bromus, two invasive species are discussed: Echinocystis lobata has become widespread along lowland rivers and streams, whereas Quercus rubra has become naturalized in forests mainly in the lowlands and at middle elevations. 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 the Supplementary materials. The maps are accompanied by comments that include additional information on the distribution, habitats, taxonomy and biology of the taxa.