Ethnobotanical and ethnoveterinary study of medicinal plants used in the municipality of Bom Princpio do Piau, Piau, Brazil

Knowledge of medicinal plants has accumulated over centuries and often represents the only therapeutic resource of small municipalities in the interior of Brazil. The objective of this study was to evaluate the knowledge and use of medicinal plants by the population of the municipality of Bom Principio do Piaui, Piaui state, for the treatment of diseases in humans and domestic animals. Interviews were conducted with 38 residents using standardized questionnaire forms, with the "snowball" technique. Fifty nine families, 98 genera and 112 species were recorded. Of these, 22.3% were indicated for the treatment of diseases in animals and 9.8% were said to cause adverse effects. The families with most species were Fabaceae (14), Euphorbiaceae (11) and Lamiaceae (6). The species with greatest use value (UV) were Myracrodruon urundeuva Allemao (0.65), Dysphania ambrosioides (L.) Mosyakin and Clemants (0.63) and Amburana cearensis (Allemao) A.C.Sm. (0.42). The leaves were the parts most frequently used (26.8%), followed by bark (21.0%). Of the 15 used categories listed in this study, those with the highest number of recorded species were related to illnesses associated with the digestive tract (102), diseases of the genitourinary system (72) and diseases of the respiratory system (60). This study revealed the importance of knowledge and use of medicinal plants in caring for the health of people and domestic animals in the municipality. In addition, the study provided information on plants of the local flora with pharmacological potential. Key words: Caatinga, medicinal plant, herbal medicine, popular knowledge.