Ecophysiological adaptation and metal accumulation in water hyacinth from two tropical rivers - Vitória, Angela P; Lage-Pinto, Frederico; Campaneli, Leonardo B; Almeida, Marcelo G; Souza, Cristina M. M; Rezende, Carlos E; Azevedo, Ricardo A; Oliveira, Jurandi G. (Brazilian Journal of Plant Physiology, 2010)