Pharmacognosy is defined as a branch of bioscience which treats in detail medicinal & related products of crude or primary type obtained from plant, animal & mineral origins. In short, it is an objective study of crude drugs from natural sources treated scientifically and its encompasses the knowledge of the history, distribution, cultivation, collection, processing for market and preservation, the study of sensory, physical, chemical & structural characters and the uses of crude drugs. Pharmacognosy also includes study of other materials used in pharmacy such as suspending, disintegration & flavouring agents, filtering aids, etc and substances like antibiotics, allergens, hallucinogens and poisonous plants, immunizing agents, pesticides, raw materials for the production of oral contraceptives, etc.