New floristic records from Central Europe 4 (reports 41–53)

The fourth part of the series includes 13 new chorological records of vascular plants from Poland and Slovakia. From Poland, the first record of Rubus austroslovacus from the Vistula River valley is given as well as the first record of Erigeron ×huelsenii from Silesia. Beside this, spontaneous occurrence of Portulaca grandiflora in Kraków and P. oleracea subsp. oleracea in Suwałki has been recorded outside the cultivation. In Slovakia, new sites of endangered species Dichostylis micheliana and Stipa pulcherrima were found as well as new distribution data about Sonchus palustris and Reynoutria japonica. From railway stations, Tribulus terrestris is reported for the first time from eastern Slovakia likewise two new sites of alien species Euphorbia davidii, previously reported from only single locality in southeastern Slovakia. Alien species Xanthium spinosum was reported from the Štiavnické vrchy Mts. and also Sisyrinchium montanum in the Slanské vrchy Mts. Third report of Sagittaria latifolia in Slovakia is given with short characteristic of its coenological conditions.