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Plant macroremains from five boreholes in Poland were studied. Two of them (Huta OP-1 and Studzianna) from the northern margin of the Holy Cross Mountains, yielded several taxa. In the other three boreholes determinable fos-sil plants were sporadic, albeit important. Most of the taxa from the Huta OP-1 and Studzianna boreholes are typi-cal of the European Early Jurassic (Hettangian and Sinemurian). Both localities, although close to one another, show incertae sedis, Desmiophyllum harrisii phytes and conifers (a new species incertae sedis, Desmiophyllum harrisii Barbacka et Pacyna is herein proposed), which would suggest rather wet and warm conditions. This flora is typical of the European Province of the Euro-Sinian Region. In Studzianna the Siberian elements dominate, gymnosperms, mainly Czekanowskiales, which in-dicate a drier and colder environment. The palaeobotanical data correspond to the results of clay mineral studies, in particular the kaolinite/illite ratio in the source formations. The kaolinite content confirms a decrease in temperature and a reduction in rainfall in the late Early Hettangian and the latest Hettangian in the area.

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The material for this study was taken from various sites in the Holy Cross Mountains: Studzianna, Huta OP-1 and Przysucha P-3 (bore cores), and Odrowąż (geological outcrop). Palynological and palynofacial analyses were used to reconstruct the Upper Triassic and Lower Jurassic vegetation and palaeoenvironment of that area. Samples from all the sites are characterised by having majority of terrestrial particles. The slides were dominated by translucent phytoclasts and small opaque phytoclasts. Pollen grains and spores were also present. The presence of marine palynomorphs was not confirmed in the samples from any of the sites, dinoflagellate cysts did not occur, and there were no foraminiferal test linings. The Sporomorph EcoGroup (SEG) model (Abbink 1998) was applied to characterise the ecological types of the plant assemblages. The most frequently occurring sporomorphs were assigned to Upland, Lowland and River SEGs. Stratigraphical changes in each of the SEGs indicate differences in climatic conditions. The floristic composition of the Studzianna, Huta and Odrowąż localities inferred from sporomorphs differs somewhat from the composition reconstructed from macroremains.

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