Background: Open and public markets are the main providers of medicinal plants in urban environments. The present study evaluated the medicinal plants sold in public markets in different municipalities in the mesoregions of the state of Paraíba, northeast of Brazil, and the possible variations in the supply of these plants in the markets over the course of a year.
Methods: Thirty-five traders of medicinal plants were interviewed in four mesoregions of different climatic and phytophysiognomic characteristics (ranging from Caatinga to Atlantic Forest). The versatility of the species sold was elucidated using the Relative Importance Index (IR), and the set of species sold by each informant in each mesoregion was compared with each other by similarity analysis Anosim-One, and by the analysis of main coordinates.
Results: Punica granatum , Zingiber officinale , and Myracrodruon urundeuva were the species with the highest RI. The analysis of similarity showed distinct differences between the Sertão and all other mesoregions. The analysis highlighted that a mesoregion had an intermediate similarity pattern in relation to the others, for which we suggest the term "biocultural ecotone" or “cultotone”. The absence of 88 species in at least one of the trading locations at some stage of the fieldwork was recorded.
Conclusions: The commercialized species do not seem to have a presence / absence relationship in relation to the period of the year or the mesoregion, and there seem to have been changes in the inventory of plants commercialized in markets in recent years. We identified an intermediate zone of knowledge and use of species commercialized between the studied localities.