The polyvariety of <i>Acer negundo</i> L. individuals development in different conditions of the urbanized environment

Abstract

The paper studies the morphological and rhythmological polyvariety of the female and male A. negundo individuals development in conditionally clean and conditionally dirty habitats. The morphological polyvariety of leaves has been analyzed according to three characteristics: shape, edge and venation. Of the 5 identified leaf forms, elliptical leaves are found with a high frequency. Two forms of the edge of the leaf blade have been revealed one-piece and toothed: female trees have an increase in the occurrence of leaves with a jagged edge; in males growing in a conditionally clean habitat, the leaves were mostly whole-edged, and in a conditionally dirty one toothed. Regardless of the habitat, three types of venation are noted: regular, opposite and mixed. The most common type of venation is mixed. The revealed diversity of leaves in A. negundo, growing in conditionally clean and conditionally dirty habitats according to the three characteristics studied, indicates the manifestation of morphological polyvariety. It is established that the flowering of A. negundo depends not only on weather conditions and the degree of illumination, but also on the location of inflorescences in different tiers of the crown. Even within the same tier, the order of flowering of inflorescences is not the same. The rhythmological polyvariety of the phenophases of A. negundo flowering manifests itself in the asynchrony of flowering, this is due to the peculiarities of individuals of the generative period and is of great biological importance for this species. Apparently, atmospheric air pollution can accelerate phenophases, so male A. negundo individuals in a conditionally dirty habitat bloomed earlier than in a conditionally clean habitat.