Anatomical characters often provide strong taxonomic evidence and many times help define species whose morphological limits are in question. This study aimed to survey characters of the leaf anatomy of 16 species of Crotalaria L. occurring mostly in the cerrado (savanna) of central Brazil and in areas of restinga (coastal woodland, or sandy forest) along the coast of the country, in order to improve the current taxonomic circumscription of sections and species. Leaf samples were collected in the field and obtained from herbarium specimens. Standard techniques in plant anatomy were employed, including analyses under light and scanning electron microscopy. Many of the characters analyzed are relatively uniform, but some are diagnostic for species. At the section level, only trichomes with a base composed of radially distributed cells proved useful in the diagnosis of C. sect. Calycinae. The other characters analyzed showed interspecific variation, but no diagnostic value for recognition of the sections. At the species level, unlike the results found for sections, various characters have diagnostic value. Among the characters with diagnostic value at the species level, those related to texture, the venation pattern (such as the formation of areolas and insertion of the ribs secondary to midrib), and, in particular, the epidermis, showed potential for aiding the circumscription of some species.

Com o objetivo de estudar a absorção e translocação de Ca, Co, Fe, K e Zn em Aechmea blanchetiana, plantas foram cultivadas in vitro em meios de cultivo contendo concentrações de Zn (0,0; 0,18; 1,8; 18 e 180 mg Zn L-1). Após 16 semanas de cultivo, os sistemas aéreo e radicular foram separados e determinadas à massa seca para massa de matéria seca e para a análise por ativação com nêutrons (AAN). O procedimento consistiu em irradiar amostras e padrões no reator nuclear de pesquisa IEA-R1 por 16 h para análise por espectrometria de raios gama. O controle dos resultados foi avaliado por meio das análises dos materiais de referência certificados, com desvios padrão relativo de 9,1 % e erros inferiores a 12,9 %. Os resultados das determinações dos elementos mostraram que o Zn alterou absorção e translocação de Ca, Co, Fe, K e Zn. A espécie apresentou alta quantidade de Zn nos sistemas aéreo e radicular indicando, possivelmente, ser bioacumuladora desse elemento.

The aim of this work was to evaluate the absorption and translocation of Ca, Co, Fe, K and Zn in plants of Aechmea blanchetiana grown in in vitro conditions contaminated with Zn (0.0, 0.18, 1.8, 18 and 180 mg Zn L-1). After 16 weeks of in vitro culture, root and shoot systems (leaves and stem) were separated, dried for dry mass measurements and neutron activation analysis (NAA). The results showed that the relative standard deviations were 9.1 % and errors were less than 12.9 %. The results obtained for A. blanchetiana indicated that Zn altered the absorption and translocation of Ca, Co, Fe, K and Zn. The species showed high values of zinc in root and aerial systems possibly indicating bioaccumulation of the element.