Abstract
The second part of the publication series on the distributions of vascular plants in the Czech Republic includes grid maps of 87 taxa of the genera Antennaria, Aposeris, Astragalus, Avenula, Bidens, Carex, Cenchrus, Centunculus, Convallaria, Crocus, Cryptogramma, Cyperus, Dryopteris, Gladiolus, Gratiola, Helictochloa, Hierochloe, Lindernia, Maianthemum, Myriophyllurn, Notholaena, Nymphoides, Radiola, Schoenoplectus, Sisyrinchium, Spergularia, Tillaea, Veratrum and Veronica. The maps were produced by taxonomic experts based on all available herbarium, literature and field records.
The plants studied include 56 taxa registered in the Red List of vascular plants of the Czech Republic, some of which showed remarkable declines. Astragalus arenarius, Hierochloe odorata and H. repens, as representatives of vegetation of inland sand dunes, are critically threatened due to conversion of their habitats to arable land, local sand mining, afforestation, changes in landscape management and eutrophication followed by succession.
Each of them survives at a few localities and their populations are poor. Competitively weak wetland annuals, confined to open habitats such as exposed fishpond littorals and river beds, abandoned sand-pits and wet arable fields, have considerably declined and disappeared from large areas as a result of agriculture and fish-farming intensification, in particular fertilization and restriction of summer drainage of fishponds, and other changes in land-use.
These include Centunculus minimus, Cyperus flavescens, C. michelianus, Lindernia procumbens, Radiola linoides and Tillaea aquatica. Observed recently at a few sites only, they are all classified as critically threatened.
A map is for the first time provided also for Spergularia kurkae, a newly recognized species and a central European endemic. Astragalus asper, Schoenoplectus supinus and Veronica pumila are now extirpated from the country's flora.