Application of Ethnobotanical Indices to Assess the Diversity of Medico-magic Knowledge on Four Herbaceous Species in Benin.

Abstract Background Ethnobotanical knowledge on four herbaceous species, Phyllanthus amarus, Spilanthes uliginosa, Momordica charantia and Acalypha ciliata in Benin was investigated. Methods Thirty-six herbal medicine traders in six different markets were interviewed using a semi-structured questionnaire. The Relative Frequency Citation, Fidelity Level, Use Value and Rahman Similarity Index were calculated to assess the diversity of medico-magic knowledge. Results All informants traded P. amarus, M. charantia and A. ciliata and the majority traded S. uliginosa. Purchase in traders’ own markets was the predominant source of P. amarus, M. charantia and A. ciliata while S. uliginosa was mostly purchased in other more distant markets. A noticeable proportion of traders also collect P. amarus and M. charantia from wild populations. Phyllanthus amarus was the species most demanded by customers followed by M. charantia. Traders confirmed the scarcity of all species in recent years and climate change as well as destruction of natural habitats for logging were the most cited causes. The entire plant of P. amarus was used mainly to treat malaria, diabetes and constipation and decoction with oral administration the most frequent preparation for malaria treatment. To treat diabetes, informants mixed P. amarus with M. charantia used as a decoction with oral administration. Momordica charantia was also used to treat measles and chicken pox. Spilanthes uliginosa and A. ciliata were mostly used for their spiritual use for luck, predominantly by chewing fresh leaves or flowers, and by bathing with the ground plant mixed with soap, respectively. Overall, M. charantia had the greatest use value followed by P. amarus. The majority of traders do not plant the species. Conclusions The harvesting and trade of the species threaten their natural populations and urgent tools, including in-situ and ex-situ conservation, are needed to ensure their long-term sustainable exploitation.