(Ethnobotany, anatomy and physicochemical characterization of essential oil of Baccharis obovata Hook. et Arn. (Asteraceae: Astereae)).

(Ethnobotany, anatomy and physicochemical characterization of essential oil of Baccharis obovata Hook. et Arn. (Asteraceae: Astereae)). Baccharis obovata Hook. et Am. is an aromatic species known as "wautro", and is an important part of the Mapuche herbolarium of Patagonia Argentina. The objectives were to investigate its ethnobotany and shoot anatomy, as well as to characterize physically and chemically its essential oil. Rural informant-interviews were conducted in two Mapuche communities of Northwestern Patagonia, Argentina. In addition, we collected plant material for observation at optical and scanning environmental microscope, and for hydro-distillation of essential oil. Informants cited with a high level of consensus that this plant is principally used for hair loss, dandruff, some dermatitis, and headaches. The main leaf features were: isobilateral mesophyll, anomocytic stomata, glandular and pluricellular trichomas and squizogen cavities that secrete essential oils. Primary stem presented trichomas and secretory cavities similar to those of the leaves, collenchyma in ribs, chlorenchyma in valleys interrupted by air spaces, continuous vascular cylinder, uni-seriated and by sectors bi-seriated endodermis, discontinuous sclerenchyma, and acicular crystals in peripheral marrow cells. In terms of its essential oil, annual average yield, optimum time for distillation, relative density, specific rotation and refractive index was also obtained. B. obovata is an interesting cosmeceutical species, this work contributes to its general knowledge providing useful information for future quality control tasks, in addition to its bio-cultural conservation.