Ethnobotany of Dioscorea L. with emphasis on food value in Chepang communities in Dhading district, central Nepal

Chepang, inhabiting the rugged terrain of Mahabharat and Churia range in central Nepal, is a group of indigenous people suffering from severe food insecurity. Their ancestors lived a semi-nomadic life up to one and half century back. To a large extent, Chepang still continue their traditional way of living, which includes collection of wild tubers (‘kandamul’), hunting and fishing. Chepangs are especially connected with the tubers of Dioscorea spp. Wild and cultivated species of Dioscorea are being used as sources of carbohydrates to supplement cereal food. However, dependency on such wild food is decreasing with adoption of agriculture. In this study we documented local knowledge on the diversity and use of Dioscorea species among Chepang in Dhusa and Jogimara Village Development Committees in Dhading district. Ethnobotanical data were collected through semi-structured interviews, forest transect walk and participatory observations. Out of 13 species of Dioscorea reported from all over Nepal, 10 species have been recorded from the study area. Chepang people use one species (Dioscorea deltoidea) as detergent and the rest nine species are exclusively used as food although many of them have multiple utilities. Chepang people have diverse knowledge in the identification, processing and consumption of wild tubers of Dioscorea spp. and such knowledge might have developed as a strategy to combat severe food scarcity. Use of disproportionately higher number of Dioscorea species by a single ethnic group and within a comparatively small territory indicates very close affinity of local cultural practice and the nature. The richness of knowledge associated with wild tubers and high dependency of Chepang on them is the manifestation of severe food insecurity and traditional mode of life due to their social and economic isolation for long time.