Comparison of morphological characters of different poplar species (Populus, Salicaceae) using the example of Russian and Central Asian Tacamahaca (Spach) Penjkovsky subgenus representatives

Abstract

Statistical analysis of 10 quantitative and 9 qualitative diagnostic characters of leaves and shoots of three Russian (Populus laurifolia Ledeb., P. nigra L., P. suaveolens Fisch.) and two Central Asian (P. usbekistanica Komarov, P. macrocarpa (Schrenk.) N. Pavl. et Lipsch.) poplar species of the Tacamahaca (Spach) Penjkovsky subgenus was performed. It was shown that according to studied quantitative characters P. nigra (Aegirus section) and P. suaveolens (Tacamahaca section) belong to opposite “poles”. This could be possibly due to the fact that the first species is the most common for lowlands poplar in said group, and the second species is the most mountainous and confined to the most severe climatic conditions. The natural areas of these two species are also geographically extremely far from one another. The other three species occupy an intermediate position both in their characters, in terms of growth, and geographically. In addition, they all hybridize in nature with Populus nigra, and Populus laurifolia also with P. suaveolens, which can also explain the intermediate nature of their characters. It was shown that the leaf characters, such as leaf length and width, leaf length and width ratio etc., reflect the specificity of the studied species somewhat worse than a number of specific characters (leaf maximum width position, leaf teeth height and lateral edge radius of curvature, leaf top length and width).