Analysis of the morphological polymorphism of Phalacroloma annuum Dumort. (Asteraceae)in different types of habitats of Kamianets Transdniestria

Abstract

Phalacroloma annuum Dumort. is a North American polymorphic species with a significant diversity of phenotypes and high invasive potential. The variability of vegetative and generative organs was analysed in different types of habitats with different environmental conditions in order to determine patterns of plant adaptation to changing environmental conditions.The largest polymorphism is typical for such vegetative features as plant height, leaf shape and width and shape of leaf edge, which demonstrates the high morphological and environmental plasticity of these plants. Pubescence of plants vary by density, length and direction of hair growth, no clear dependence from environmental factors was identified. The dependence of variation features of vegetative organs of plants on ecological conditions (soil moisture, lighting) was established. Lanceolate and oblong leaves with irregularly or large toothed edges often occurred in excessive soil moisture; oblanceolate leaves with irregularly toothed edges occurred in arid habitats. Most of the studied populations have a strong correlation between width and length of leaves (r = 0.73–0.85). The weakest correlation was observed between shoot height and leaf size (r = 0.04–0.05). The variability of inflorescence characters is low (basket size, tongue flower length) and average (length and width of the wrapper leaves and tubular flower, width of tongue flower and its colour). The weakest correlation was observed between basket size and the following features: wrapper leaves length (r = 0.53), wrapper leaves width (r = 0.55), tongue flower length (r = 0.47), tongue flower width (r = 0.63), tubular flower length (r = 0.2). The weakest correlation was observed between basket size and tubular flower width (r = 0.07). It was established that plants of Ph. annuum, which are related to anthropogenic habitats, have greatest variability of morphological features and increased quantitative parameters.

Keywords

• phalacroloma annuum
• morphological features
• polymorphism
• habitat
• kamianets transdniestria