| ABSTRACT Seasonally-dry environments of the Neotropics, such as the South American Chaco, exert selective pressures on vegetation through a pronounced water deficit. We describe the underground system and leaf anatomy of three species of Asteraceae from the Brazilian portion of the Chaco (Pterocaulon purpurascens Malme, Wedelia trichostephia DC., and Pectis gardneri Baker), aiming to describe their structural and adaptive features using standard plant anatomy techniques. Pterocaulon purpurascens and W. trichostephia exhibited slightly thickened xylopodia, with gemmiferous character and self-grafted stem shoots; Pectis gardneri displayed a slightly-thickened tuberous root with storage substances. Longitudinal sequences of cells with highly thickened walls... |
