Pharmacognosy:  This is the study of medicinal plants. Pharmacognosy is a kind of the study of medicines which are derived from natural sources. The American Society of Pharmacognosy defines pharmacognosy as "the study of the chemical, physical, biochemical or biological properties of drugs, potential drugs, and drug substances of natural origin as well as the search for new drugs from natural sources."

Although mostly pharmacognostic studies focus on plants or medicines which are derived from plants, other types of organisms are also regarded as pharmacognostically interesting. In particular, many types of microbes like bacteria, fungi, etc.are recently various marine organisms.