Several weeds growing widespread in west-central Argentina have potential utility as sources of essential oils. We made a preliminary screening in order to select the most interesting species not analyzed previously. Heterotheca latifolia Buck. (Compositae), one of them, is a foreign (North American) species that was brought to Argentina as contaminant of commercial samples of seeds. It was first detected in 1972 and currently covers extensive regions of both unworked or cultivated lots in all the central area of San Luis Province, Argentina, Evidently, it has found a suitable climate, and it is one of the dominant species in this habitat. Named “alcanfor” (camphor) obviously for its fragrance, it has no known medicinal or economical use; on the contrary, it is considered a weed and is readily destroyed.
Although there are several papers in the bibliography about this genus, no one has studied or described its aroma. We have identified in a previous work the main constituents of the essential oil from its aereal parts and showed an olfactive evaluation that was further confirmed by the assistance of the Symposium of Natural Aromatic and Medicinal Resources, held in Necochea, Argentina in 1984. The confirmation of those compounds and identification of some others present in minor quantities are given in this paper. Furthermore, we present a critical analysis of the potential economic value of this essence for the fragrance industry.