The history of medicine dates back perhaps to the origin of human race and since time immemorial, man has made use of plants for the treatment of disease. Application of various herbal preparations which are highly effective for curing many diseases seem to have been in practice as early as 400 BC. The earliest reference to the use of medicinal herbs as a cure for a disease was found in Ebers Papyrus (2600 BC). In India, references to the curative properties of herbs in Rig Veda (period estimate between 3500-1800 BC) seem to the earliest records of use of plants in medicine. However, these references are very brief. More detailed account is available in the Ayur veda (about 2500 BC), the Indian System of Medicine. After the Vedas, appeared the two most important works on Indian System of Medicine, the Charak-Samhita (1000 BC) and Susruta-Samhita (800 BC). The Unani system of medicine further enriched the Herbal Materia Medica. Sheikh Abu Ali Seena (980-1033 AD), the author of AL QANOON described various plant medicines in his book Adviya Qalbia (Mamtani and Mamtani, 2005).