Morphological variation of Cosmos bipinnatus (Asteraceae) and its relation to abiotic variables in central Mexico

摘要

Background Morphological variability can lead to serious taxonomic problems in species with wide distribution ranges. Although morphological variability is partly due to ontogenetic programming, abiotic variables can also exert a significant effect on micro- and macromorphological characters. In this paper, we studied the morphological variability (43 characters) of Cosmos bipinnatus associated to different vegetation types in central Mexico. We searched for significant correlations between the overall morphology of C. bipinnatus and abiotic variables such as altitude and soil parameters (pH, organic matter content, NH₄, NO₃, PO₄, total N and total P content). We also analyzed the Simplified Relative Distance Plasticity Index (RDPI_s).