Morpho-anatomical and essential oil analysis of four species of Aldama la Llave (Asteraceae: Heliantheae)

Abstract

The genus Viguiera sensu lato has serious phylogenetic problems that show the non-monophyletic origin of the group and many efforts have been applied to obtain new data that can solve these problems. The genus Viguiera sensu lato has serious phylogenetic problems that show that its non-monophyletic origin and many efforts have been applied to obtain new data that can solve them. In 2011 an article was published in which the authors propose the transfer of the South American species from the Viguiera genus to the Aldama genus. However, the Brazilian expert on this genus considers that additional studies are needed because the circumscription for the South American species is not well established. Thus, the species Aldama anchusifolia (DC) E.E.Schill. & Panero, A. megapotamica (Malme) Magenta & Pirani, A. nudibasilaris (S.F.Blake) E.E.Schill. & Panero e A. pilosa (Baker) E.E.Schill. & Panero will be discussed on the morphology and anatomy of vegetative aerial and underground organs, as well as the anatomy and histochemistry of secretory structures and the chemical composition of essential oil with the aim of finding characters that could be used to distinguish these species. For structural analyzes, will be made permanent and semipermanent slides following the usual histological techniques. The leaf surface and stem analyzes will be carried out in a scanning electron microscope. The essential oil extraction will be performed by hydrodistillation in a Clevenger-type system. The collections will be held in grassland formations of South and Southeast regions of Brazil, and the sample size is equivalent to three. (AU)