Anatomia foliar e do xilema secundário de espécies de Aspidosperma Mart. & Zucc. (Apocynaceae).

Abstract

The genus Aspidosperma Mart. & Zucc. is often used for its wood in the Amazon. This genus is taxonomically complex because of morphologically similar species. Anatomy is a resource for distinguishing these taxa. The objective of this study was to anatomically characterize the leaves and wood of Aspidosperma excelsum, A. carapanauba, A. desmanthum, and A. spruceanum, as a contribuition to their identification. Standard wood and leaf anatomical techniques were used. The studied species showed similarities for: epicuticular waxes, thick cuticle, bicolatoral vascular bundles, filiform trichomes, straight-sided epidermal cells pentagonal to hexagonal. Differences were seen in cuticular ornamentation, organization of vascular bundles in pedicles, and in leaf architecture, such that two groups can be formed. Wood of the studied species is quite similar, having the following characteristics in common: homogeneous rays uniseriate to triseriate, small and diffuse solitary pores. The principal structure for distinguishing these species is the axial parenchyma that varies from diffuse apotracheal to aliform paratracheal with losangular extention with short aleta. These anatomical structures, both of the leaves and the wood, are sufficient to distinguish the studied species.