Geographic patterns of morphological variation in Turnera sidoides L. subsp. pinnatifida (Juss. Ex Poir.) Arbo (Turneraceae)

VIVIANA GRISELDA SOLIS NEFFA

PLANT SYSTEMATICS AND EVOLUTION

SPRINGER WIEN

Año: 2010 vol. 284 p. 231 - 253

0378-2697

With the objective of contributing to understanding the patterns of variation within the Turnera sidoides complex, a detailed evaluation of morphological variation along the range of T. sidoides subsp. pinnatifida was performed. A multivariate analysis based on leaf traits and flower colour data enabled differentiation of five morphotypes. Common-garden experiments demonstrated that the morphological variants have a strong genetic basis. It was also found that the morphotypes are geographically structured along the subspecies range, display different habitat preferences, and occur in regions with different climatic regimes. Although these results are suggestive of adaptive differentiation of T. sidoides subsp. pinnatifida, comparisons between morphological and bioclimatic ordinations showed that the patterns observed cannot be fully explained by current climatic conditions. It is proposed that Miocene–Pleistocene events may explain the origin of the five morphotypes and that current climatic and ecological factors may be contributing to the maintenance of the extent and patterns of morphological  differentiation in T. sidoides subsp. pinnatifida.