Title : Measuring the importance and use of plant species on a list. What are the factors that increase the use of one plant over another?
Ethnobotanical indices are important quantitative indicators. Although indexes are subjective, they help to understand the level of importance or the choice of a plant to another for one purpose. In 2019, a survey was conducted in Paraguay, information from 384 participants was collected about plants species (Ps) used against gastrointestinal nematodes (GIN). One of the objectives was to measure the importance and use of Ps in the study population using two indices, namely: Salience index (SI) and Use Value (UV) aimed to describe the factors involved in the choice of Ps for use in traditional medicine. As result, 16 Ps were listed, among them, Chenopodium ambrosioides (SI 0.74; UV 0,74) were considered of high cultural important and Aloysia polystachya (SI -0,039; UV 0,01) were considered as minor important for this purpose. As we appreciate, the use is associated with popularity (citation). The importance depends on the number of citations but also, for the position in the rank when they were cited. The use and the importance are linked. Therefore, responses depend on marketing, that is, on the information available such as: availability, diffusion of their properties by experts, use and recommendation. Those factors making the name easy to remember and a high position on a free list as if it were a commercial brand. More studies are recommended comparing uses, importance and validation of claimed effects, to validate local knowledge and to protect Ps, because “trendy” ones are more exposed to overexploitation.