Additions to the flora of the Czech Republic. XVI.

This sixteenth part of floristic contributions includes the data of taxa newly discovered in the territory of the Czech Republic (Amaranthus emarginatus subsp. emarginatus, A. emarginatus subsp. pseudogracilis, Asplenium ×woynarianum, Pilosella glomerata × P. bauhini, Sorbus ×kitaibeliana, Symphytum tuberosum subsp. angustifolium, Taraxacum hahnii and Urtica dioica × U. kioviensis) and data of alien species found in the Czech Republic for the first time (Corydalis cheilanthifolia, Cyclospermum leptophyllum, Euphorbia serpens, Houttuynia cordata, Limonium gmelini, Salvia hispanica) are summarized. Furthermore, criticaly endangered species (according to the Red List of Vascular Plants of the Czech Republic) are reported from new localities (e. g. Aira caryophyllea, Asplenium trichomanes subsp. pachyrachis, Chenopodium murale, Clematis integrifolia, Crepis setosa, Eleocharis quinqueflora, Hieracium obscuratum, Juncus atratus, Orchis ustulata, Orobanche elatior, Pilosella macranthela, Taraxacum cognatum, Trifolium striatum and Viola elatior). Finally, less rare and threatened species are reported from phytogeographical districts where they had not been recorded yet (Chenopodium foliosum, Draba muralis, Erechtites hieraciifolia, Hieracium caesium and Pilosella scandinavica).