Ethnobotanical authentication and identification of Khrog-sman (lower elevation medicinal plants) of Bhutan
Ethnopharmacological relevance: The Bhutanese form of g.so-ba-rig-pa medicine, which is a scholarly medical system, belongs to a larger system of medicinal corpus that spreads from Mongolia to India. It uses medicinal plants as a bulk ingredient but only 'Higher Elevation Medicinal Plants' have been botanically identified so far. Our study reports the botanical identification of 'Lower Elevation Medicinal Plants' and their ethnomedical uses. Aim of the study: To botanically identify the 'Lower Elevation Medicinal Plants' used in Bhutanese traditional medicine. Materials and methods: A five stage process was conducted which consisted of: (1) a survey of specialized ancient ethnomedical literatures (Pharmacopoeias and formularies); (2) freely listing the 'Lower Elevation Medicinal Plants' reported in the ancient Bhutanese medical texts and translating their ethnomedical uses in equivalent terms of English; (3) making field visits, collecting herbarium specimens and photographs, and spot identification of plants; (4) double blind testing of Bhutanese traditional medicine practitioners for authentication and standardization of Bhutanese g.so-ba-rig-pa names; (5) organising workshops for open forum discussions on medicinal plants involving Traditional Physicians and other professional participants of the relevant areas. Results: We identified the botanical names of 113 'Lower Elevation Medicinal Plants' belonging to 68 families and 104 genera. Out of 113 medicinal plant species identified, 92 species are currently used in Bhutan and the remaining 21 species were not used in the current formulation, but described in the Bhutanese traditional medical texts. The identification of these 21 species was achieved both ethnomedically and botanically for the first time. Out of the 28 plant species that are currently imported from India, we found for the first time, even to the knowledge of Traditional Physicians, that 16 of them are actually growing abundantly in Bhutan. Among the plant parts collected, seeds were the most prominent followed by fruits and then roots. Conclusions: Our study identified 113 'Lower Elevation Medicinal Plants' out of which 92 of them are used daily in formulating 102 multi-ingredient prescription medicines in Bhutan.