Leaf anatomy of seven endemic species of Glicophyllum (Malpighiaceae) in Brazil.

Glicophyllum is well supported, presenting four homoplasies, easily differentiated from the other genera of the clade due to characteristics related to the reproductive organs, which can make the identification of their species difficult when they are not in the reproductive phase. Therefore, there are provided the leaf anatomical and morphological description of the leaf glands of seven species of Glicophyllum to assist in the identification of their species. The samples for the study were obtained from several national and international herbaria, sectioned freehand, stained with basic fuchsin - astra blue and compared through a binary matrix using the Sorensen's coefficient in the MVSP software. Among the leaf anatomical characters found, the following stand out: presence/absence of trichomes; petiole contour; contour of the main vein; organization of the mesophyll, presence/absence of bundle sheath extension and the surface of the glands. In this study, an identification key with leaf anatomical data is presented for the first time, demonstrating the applicability of leaf anatomy for the taxonomy of Glicophyllum. In the multivariate analysis, it is observed that the characteristics of leaf venation and topology of the glands are more representative to differentiate the taxa. Therefore, the data obtained can support future taxonomic and phylogenetic studies of the genus.

Evaluation of micro-energy dispersive X-ray fluorescence and histochemical tests for aluminium detection in plants from High Altitude Rocky Complexes, Southeast Brazil.

The soils developed under High Altitude Rocky Complexes in Brazil are generally of very low chemical fertility, with low base saturation and high exchangeable aluminium concentration. This stressful condition imposes evolutionary pressures that lead to ecological success of plant species that are able to tolerate or accumulate high amounts of aluminium. Several analytical methods are currently available for elemental mapping of biological structures, such as micro-X-ray fluorescence (µ-EDX) and histochemical tests. The aim of this study was to combine µ-EDX analysis and histochemical tests to quantify aluminium in plants from High Altitude Rocky Complexes, identifying the main sites for Al-accumulation. Among the studied species, five showed total Al concentration higher than 1000 mg kg-1. The main Al-hyperaccumulator plants, Lavoisiera pectinata, Lycopodium clavatum and Trembleya parviflora presented positive reactions in the histochemical tests using Chrome Azurol and Aluminon. Strong positive correlations were observed between the total Al concentrations and data obtained by µ-EDX analysis. The µ-EDX analysis is a potential tool to map and quantify Al in hyperaccumulator species, and a valuable technique due to its non-destructive capacity. Histochemical tests can be helpful to indicate the accumulation pattern of samples before they are submitted for further µ-EDX scrutiny.