W pracy przedstawiono warunki występowania oraz strukturę populacji tłustosza pospolitego dwubarwnego na jedynym, aktualnie znanym stanowisku w polskich Karpatach. Stwierdzono, że z tłustoszem współwystępuje 115 gatunków roślin naczyniowych oraz 8 gatunków mchów. Wykazano, że jego osobniki generatywne osiągają większe rozmiary niż osobniki wegetatywne i wytwarzają więcej liści w różyczce, których powierzchnia jest większa od powierzchni liści osobników wegetatywnych. Aktualnie populacja tłustosza nie jest bezpośrednio zagrożona, ale w celu ochrony jej przed postępującą sukcesją roślinności drzewiastej podjęto umiarkowane zabiegi ochrony czynnej
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Bicoloured common butterwort has deeply incised sepals, white corolla lobes and purple spur. Conditions of occurrence and size structure of bicoloured common butterwort [critically endangered (CR) species] were investigated within a Carex davalliana alkaline fen located in Beskid Niski in southern Poland. This site is the only one known actually in Polish Carpathians. At the beginning of this study all species were identified within study area (1 ha). Next along one transect consisted of 26 squares (with area of 0.5 square meters per one plot) the average percent cover of species was estimated. Within a 13 square meter area (26 plots), a total of 66 different plant species were recorded. In comparison, 115 species were identified within the study area. The population counts butterwort 594 individuals. Its population density varied from 2–292 (average 33) plants per 1 square meter. Only 168 plants were measured within 11 plots out of 33 plots (26 plots were located along the transect and additionally 7 of them were chosen randomly within study area). Number of flowering and non-flowering individuals, number of leaves per rosette, population density of this species, length of the longest and the smallest leaf of rosette and height of leafless scapes were recorded. Rate of flowering plants, in relation to total number of individuals, is equal to 51%. Most flowering plants in populations produced one or two flowers per season. Flowers were born singly on leafless 6–24 cm scapes. Butterwort plants produced a basal rosette of entire leaves. The rosette had 2–21 leaves. The average length of the longest leaf varied from 1 cm to 9 cm. The plant size was estimated both as the length of the largest leaf of rosette, and as the number of leaves times the length of the longest leaf as this measure was found by Svensson (1993) to have a higher correlation with the individual weight and flowers/fruits production. Flowering individuals are larger in comparison to non flowering plants. They had more and longer leaves and larger leaf area per rosette. The distribution pattern of the species seems to be affected by a land use and distribution of microsites. It seems that the patchiness of this area offers good conditions for the species.