Diversity, knowledge and use of medicinal plants in Abay Chomen District, Horo Guduru Wollega Zone, Oromia Region of Ethiopia

An ethnobotanical study of medicinal plants was conducted in Abay Chomen District, Western Ethiopia from September 2014 to August 2015. This study documents indigenous medicinal plant utilization, management and the threats affecting them. Ethnobotanical data were collected using semi structured interviews, field observations, preference and direct matrix ranking with traditional medicine practitioners. The data were analyzed using descriptive statistics; informant consensus factor and fidelity level using MS-Excel 2010. The ethno-medicinal use of 93 plant species belonging to 85 genera and 52 families were documented in the study area. The highest family in terms of species number is Fabaceae. Herbs were dominant (31.3%) flora followed by shrubs (30.1%). Most of the medicinal species (52.7%) were collected from the wild. Most of the plants (60.2%) were reportedly used to treat human diseases. The most frequently used plant parts were leaves (34.68%), followed by roots (23.39%). Fresh plant parts were used mostly (53.3%) followed by dried (29.3%) and the remaining (17.4%) either in fresh or dried. Among the preparations, pounding was the dominant (34.1%) form followed by powdering (13.29%). The remedial administration was mostly oral (54.91%) followed by dermal (30.64%). The highest (88.89%) informant consensus factor was associated with Ocimum urticfoluim followed by Allium sativum (86.67%). The fidelity level of Allium sativum was calculated irrespective of malaria treatment. Direct matrix analysis showed that Carissa spinarum was the most important species followed by Syzygium guineense indicating high utility value of these species for the local community. The principal threatening factors reported were deforestation followed by agricultural expansion.   Key words: Ethno-medicine, ethnobotany, Abay Chomen District, medicinal plants, traditional healers.