This study documents information on significant ethnomedicinal plants, which was collected from the traditional healers of three indigenous communities of Bangladesh. The documented data were quantitatively analyzed for the first time in this area. The information was obtained through open-ended, semi-structured questionnaires. The benefits, importance and coverage of ethnomedicine were expressed through several quantitative indices including Informant Consensus Factor (ICF), Use Value (UV), Frequency of Citation (FC), Relative Frequency of Citation (RFC) and Relative Importance Index (RI). The agreement of homogeneity between the present and previous studies and among the indigenous communities was evaluated using the Jaccard Index (JI). A total of 159 ethnomedicinal plant species, which were distributed in 132 genera under 62 families, were documented from 174 informants. Of these, 128 plants were native and 31 were exotic. Of a majority of documented species, herbs and leaves were the most utilized plant parts for the preparation of ethnomedicines (45.28%) whereas pastes (63.03%) were the most popular formulations. Among the documented species, the dominant families were the Asteraceae (14 species) and the Lamiaceae (12 species). The highest ICF value was 0.77 for digestive system disorders. Based on UVs, the five most commonly used ethnomedicinal plant species in the study area were Duabanga grandiflora (0.43), Zingiber officinale (0.41), Congea tomentosa (0.40), Matricaria chamomilla (0.33) and Engelhardtia spicata (0.28). The highest RFC was recorded for Rauvolfia serpentina (0.25). The highest RI value was calculated for both Scoparia dulcis and Leucas aspera (0.83). Importantly, 16 species were reported with new therapeutic uses and to our knowledge, 7 species described herein have never been ethnobotanically and pharmacologically studied, viz: Agastache urticifolia, Asarum cordifolium, C. tomentosa, E. spicata, Hypserpa nitida, Merremia vitifolia and Smilax odoratissima. The present study showed that traditional treatment using medicinal plants is still widespread in the study area. Documentation of new ethnomedicinal species with their therapeutic uses shall promote further phytochemical and pharmacological investigations and possibly, lead to the development of new drugs.

The present study documents the ethnomedicinal knowledge among the traditional healers of the Pangkhua indigenous community of Bangladesh. The documented data from this area was quantitatively analyzed for the first time. We aimed to record ethnomedicinal information from both the traditional healers and also the elderly men and women of the community, in order to compile and document all available information concerning plant use and preserve it for the coming generations. We aimed to compare how already known species are used compared to elsewhere and particularly to highlight new ethnomedicinal plant species alongside their therapeutic use(s). All ethnomedicinal information was collected following established techniques. Open-ended and semi-structured techniques were primarily utilized. Data was analyzed using different quantitative indices. The level of homogeneity between information provided by different informants was calculated using the Informant Consensus Factor. All recorded plant species are presented in tabular format, alongside corresponding ethnomedicinal usage information. This investigation revealed the traditional use of 117 plant species, distributed among 104 genera and belonging to 54 families. There was strong agreement among the informants regarding ethnomedicinal uses of plants, with Factor of Informant Consensus (FIC) values ranging from 0.50 to 0.66, with the highest number of species (49) being used for the treatment of digestive system disorders (FIC 0.66). In contrast, the least agreement (FIC = 0.50) between informants regarding therapeutic uses was observed for plants used to treat urinary disorders. The present study was compared with 43 prior ethnomedicinal studies, conducted both nationally and in neighboring countries, and the results revealed that the Jaccard index (JI) ranged from 1.65 to 33.00. The highest degree of similarity (33.00) was found with another study conducted in Bangladesh, while the lowest degree of similarity (1.65) was found with a study conducted in Pakistan. This study recorded 12 new ethnomedicinal plant species, of which 6 have never been studied pharmacologically to date. This study showed that the Pangkhua community still depends substantially on ethnomedicinal plants for the treatment of various ailments and diseases and that several of these plants are used in novel ways or represented their first instances of use for medicinal applications.