Background and Purpose: Since illnesses have always accompanied human life, using medicinal plants has a history as long as the history of mankind. Documents in the history of medicine and pharmacy belonging to several thousand years ago contain valuable experiences and information on herbal medicine. This study aims to assess medicinal plants used by herbalists and indigenous people in Darreh Shahr located in Ilam province.

Materials and Methods: Data was collected via face-to-face semi-structured interviews with six herbalists and 25 indigenous people from different villages with various ethnicities. To improve the accuracy of collected information, the first author spent 20 days working in a herbal medicine store. Additionally, participatory field walk with indigenous people was performed during data collection.

Results: The results showed that the type of consumed medicinal plants varies from season to season. Descurainia sophia, Lalementia iberica, Cichorium intybus, Mentha piperita and Citrus aurantium were used in spring and summer, while Zataria multiflora, Foeniculum vulgare, Cuminum cyminium, Cinnamomum zeylancum, Zingiber officinale, Satureja khuzistanica, Allium iranicum, Altheae officinalis, Malva sylvestris and Anthemis cotula were used in autumn and winter. Most identified species belonged to Lamiaceae, Asteraceae and Apiaceae families. Results of this study also indicated that medicinal plants are mostly used for food preparation, curing colds, and kidney and gastrointestinal illnesses. It was found that aerial parts, especially flowers were the most frequently used parts, while the root zone was used least.

Conclusion: The current study provides valuable data for documentation of traditional knowledge of medicinal plants among herbalists and indigenous people. Moreover, it has applications for decision-makers and planners in developing medicinal plants economy in the region.