Aluminum and nutrient concentrations in species native to central Brazil

Forty species from eight angiosperm families occurring in the Cerrado and neighboring regions of Bahia and Minas Gerais in Brazil were examined for aluminum (Al) content. Twenty species from four families (Leguminosae, Compositae, Rubiaceae, and Melastomataceae) were found to have leaf Al contents above 1000 mg/kg dry wt. This constitutes the first record of nodulating legumes accumulating Al, most notably certain species of the caesalpinioid genus Chamaecrista. The amount of Al in the leaves of the accumulating species ranged from 16,390 mg/kg dry wt in Chamaecrista repens to 1012 mg/kg dry wt in Chamaecrista viscosa. These native plants on virgin soil had no visual adverse effects from the high concentration of Al, in fact, they seemed to have an efficient mechanism for absorbing all nutrients from the soil and growing and flourishing at levels considered very deficient for other crop species. The percentage of other foliar cations was not significantly different between Al accumulating or non-accumulating species.