The plant kingdom is the most essential to human well being in providing basic human needs. Human beings used plants for the purpose of disease control and prevention since time immemorial. Early humans acquired the knowledge on the utilization of plants for disease prevention and curative purposes through many years experience, careful observations and trial and error experiments (Sofowora, 1982; Martin, 1995). Such ethnomedicinal knowledge involves traditional diagnosis, collection of raw materials, preparation of remedies and prescription to the patients. More than 35,000 plant species are reported as being used across the globe for medicinal purposes (Lewington, 1993) and in Ethiopia more than 800 plant species have been employed as medicinal plants (Tesema et al., 2002). There is a considerable global interest in tapping the accumulated knowledge of traditional medicine; researches are being carried out in many countries with the aim of increasing the use of