There have been investigated some ecological and physiological aspects of the leaf appearance process on pedunculate oak (Quercus robur L.). It has been proved that the leaf expansion dynamics of oak offspring’s in years with different spring temperatures is the result of the specific influence of ,,fairground” temperature gradient that specifically affects the oak leaf expansion for different oak genotypes. Due to the different heterozygosity degrees of maternal trees, the inbred progeny is characterized by specific leaf time and duration, more restricted or rather longer. The descendants also tend to inherit the leaf tim es characteristic to seed trees.