Acta Societatis Botanicorum Poloniae Article ID: 901 DOI: 10.5586/asbp.901 ORIGINAL RESEARCH PAPER in FLORISTICS AND PLANT CONSERVATION Publication History Received: 2020-04-26 Differences in Potamogeton praelongus Accepted: 2021-02-02 Published: 2021-05-15 Morphology and Habitats in Europe Handling Editor 1 1* 1 Zygmunt Dajdok; University of Zuzana Kozelková , Romana Prausová , Zina Tomášová , Wrocław, Poland; Lenka Šafářová2 https://orcid.org/0000-0002- 1 8386-5426 Department of Biology, University of Hradec Králové, Hradec Králové, 500 03, Czech Republic 2East Bohemian Museum in Pardubice, Pardubice, 530 02, Czech Republic Authors’ Contributions * ZK and RP: collection of feld To whom correspondence should be addressed. Email:
[email protected] data and their evaluation; ZT: collection of feld data; LŠ: statistical analyses Abstract One of the most southern European occurrences of Potamogeton praelongus is in Funding the Czech Republic (CR), with only one native population in the Orlice River The study was fnanced by grants from the Ministry of foodplain in Eastern Bohemia, the only surviving site from 10 Czech localities Education of the Czech Republic known 45 years ago. is species is critically endangered in the CR and needs to – PřF UHK No. 2112/2014, be actively protected with a rescue program. e number of P. praelongus sites 2111/2015, 2107/2016, increases along a latitudinal gradient, from Central to North Europe (CR, Poland, 2113/2018, 2115/2019 and by funds awarded by EEA/Norway Sweden, and Norway), and correlates with improving conditions (water and the Ministry of Environment transparency and nutrient content in water) for this species along this gradient.