Morphology and environment: geographic distribution, ecological disjunction, and morphological variation in Actinocephalus polyanthus (Bong.) Sano (Eriocaulaceae)

Abstract

AbstractMost Brazilian Eriocaulaceae have highly restricted geographic distributions. Actinocephalus polyanthus (Bong.) Sano is one of the few widely distributed species; furthermore this distribution includes an interesting ecological disjunction. Actinocephalus polyanthus occurs in montane areas from northern Minas Gerais to Paraná, as well as coastal sand dune habitats in Santa Catarina and Rio Grande do Sul. In attempt to investigate whether there is any correlation between the ecological disjunction and the patterns of morphology exhibited by this species, eight populations were sampled covering the geographic distribution and the ecological disjunction. We used multivariate statistical methods (UPGMA, PCA and DF) to describe the morphology, and to verify its correlation with its distribution and habitat. We conclude that sand dune populations are morphologically different from the montane populations. The main difference in these plants is the robustness. The sand dune plants are significantly smaller than the plants from montane areas. We also verified that these populations have a morphological identity. The occurrence of this species in such diverse environments may reflect the morphological diversity of the various populations of the species, and may be the primary cause of the difference in these populations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)