On the basis of palynologic and palynofacies data from the Biały Kamień Formation in the Intra-Sudetic Basin (ISB), the composition of parent plant communities and the depositional environment during sedimentation of this unit were reconstructed. The results were then compared with earlier published palynological data from the stratigraphically older and younger lithostratigraphical units, the Wałbrzych and Žacléř formations, allowing a general interpretation of floristic and environmental changes throughout the Serpukhovian to Moscovian interval. The floras in the Serpukhovian resemble the composition in the Moscovian. In both, their main feature is low lycopsid abundance, indicating relatively dry palaeoclimatic conditions. In contrast, the Bashkirian records a gradual increase in lycopsids and sphenopsids, peaking in the late Bashkirian during the maximum humid phase. This was followed in the Moscovian by a marked decline in lycopsids and a shift toward fern dominance, reflecting a transition to a drier climate associated with the First Dry Interval, proposed by Phillips and Peppers (1984). At the same time, the miospore record shows no evidence of abrupt floristic changes, contradicting the concept of a “floristic leap” at the Namurian A/B boundary.
