Znaczenie badań nad zmiennoscią liści grabu dla celów paleobotanicznych [Studies on the variability of hornbeam-leaves and their importance for paleobotany]

Abstract

The aim of the investigations on the variability of the leves of Carpinus betulus was to characterize a chosen population on the basis of all types of its leaves. The results obtained from the measurements of the leaves, which provided a picture of their variability, were compared with the autumn fall of the same population, i.e. with the material which some time might become fossil material. It appeared that three fundamental types of leaves may be distinguished on the shoots of Carpinus betulus: l. short, broad, roundish or egg-shaped leaves with broad apical angles and a heart-shaped base, which grew out of the first nodes, 2. slim leaves with acute apical and basal angles, their broadest part situated high, which were encountered on nodes VII-X of the long shoots, and 3. large, oval leaves derived from nodes IV-VI and regarded as typical of the species Carpinus betulus. The asymmetry of the base of blade appeared to be an important character. This asymmetry vanished gradually from node to node towards the apex of shoot.