What’s in a name? Revisiting medicinal and religious plants at an Amazonian market

BACKGROUND: In spite of an increasing number of ethnobotanical market surveys in the past decades, few studies compare changes in plant species trade over time. The open-air market Ver-o-Peso (VOP) in Belém, located near the mouth of the Amazon River in the state of Pará, Brazil, is known for its wide variety of medicinal plants. A survey of VOP was published in 1984, but it remains unknown to what extent its botanical composition changed over 34 years. Furthermore, in northern Brazil, little attention has been given to the origins of the vernacular names of these plants. Our aim is to give an up-to-date overview of the VOP medicinal plant market, concentrating on changes in species composition and vernacular names over time. METHODS: We collected medicinal plants and vernacular names at VOP in August 2018. We identified most plants at the Museo Paraense Emilio Goeldi Herbarium, where we also deposited vouchers and specimen labels. We compared our species composition data to the 1984 inventory by Van den Berg. Furthermore, we investigated the etymologies of the vernacular plant names. RESULTS: We recorded 155 plant specimens and 165 corresponding vernacular names, and collected 146 specimens from the medicinal and ritual stalls of VOP reporting 86 species formerly not recorded at this market. Vernacular names had mostly Portuguese roots, followed by Tupi and African ones. We found 30 species also documented in 1984, and vernacular names that overlapped between both surveys were used for the same botanical species or genus, indicating that vernacular names have changed little in the past decades. Lastly, we found 26 more introduced species sold at VOP compared to 1984. CONCLUSIONS: Forest degradation and deforestation, prevalence of diseases, and methodological factors may play a role in the differences we found in our survey compared to 1984. Of the plants that did overlap between the two surveys, vernacular names of these plants were hardly different. Lastly, the lingual origins of the vernacular names in our survey and the origins of the plant species reflect the history of the intricate syncretism of medicinal plant practices of indigenous, Afro-Brazilian and European origins in Belém. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13002-021-00433-4.