Until now, Dryopteris remota was only recorded in the Czech Republic from the Moravian Karst, ca 70 years ago. This record is mentioned in some studies, but references to the data’s origin have always been missing. For this reason it was uncertain whether D. remota was still present in the Czech Republic. Recently, the records from the Moravian Karst were verified by re-examination of original herbarium specimens. In 2002 a specimen of D. remota was found for the first time in Bohemia, close to the village of Ktiš, on a slope of Malý Plešný hill in the foothills of the Bohemian Forest (S Bohemia). At this locality only one plant occurred on the boundary between Lonicera nigra-shrub and spruce-beech-fir forest, on a gneiss outcrop. Determination of the Czech specimens of D. remota was based on comparisons with macro- and micromorphological characters of both Alpine (Upper Austria) and Carpathian (West Ukraine) specimens, as well as descriptions in the literature. A detailed morphological description and comparison with similar taxa are included. A map of its distribution within the Czech Republic as well as a map of the distribution of D. remota worldwide is also presented. It is suggested that D. remota be designated a critically endangered plant species in the Czech Republic.
Flow cytometry measurements confirmed the occurrence of Polypodium ×mantoniae (P. interjectum × P. vulgare) at three localities in the eastern part of the Czech Republic (Blansko and Rudice N of Brno and Javoříčko WNW of Olomouc). Nuclear DNA contents (± Sx) were determined for P. vulgare (2C = 29.00 ± 0.32 pg), P. ×mantoniae (2C = 37.18 ± 0.38 pg) and P. interjectum (2C = 45.24 ± 0.31 pg) using a PAS Partec GmbH flow cytometer (PI staining / standard Vicia faba, 2C = 26.9 pg). The relative DNA content ratio was measured in all pairs of taxa (± Sx range), i.e. P. ×mantoniae : P. vulgare = 1.340 ± 0.008; P. interjectum : P. vulgare = 1.681 ± 0.003; P. interjectum : P. ×mantoniae = 1.255 ± 0.008. Six new localities for Polypodium interjectum were found in the region of Moravský Kras (= Moravian Karst, N of Brno). From the PI/DAPI index it can be inferred that the AT/GC ratio (or heterochromatin occurrence) is 1.05× bigger in P. ×mantoniae than in P. vulgare and 1.08× bigger in P. interjectum than in P. vulgare. Anatomical data (number of thick- walled cells in the anulus, spore length and stomata length) of selected specimens and live samples from the Czech Republic were in good agreement with the range of variation of these features published by earlier authors from other European countries. A brief historical survey of the knowledge of P. interjectum in the Czech Republic is included.