The word "pharmacognosy" is derived from two Greek words φάρμακον pharmakon (drug), and γνῶσις gnosis (knowledge). The term "pharmacognosy" was used for the first time by the Austrian physician Schmidt in 1811 and 1815 by Crr. Anotheus Seydler in a work titled Analecta Pharmacognostica.
Originally—during the 19th century and the beginning of the 20th century—"pharmacognosy" was used to define the branch of medicine or commodity sciences (Warenkunde in German) which deals with drugs in their crude, or unprepared, form. Crude drugs are the dried, unprepared material of plant, animal or mineral origin, used for medicine. The study of these materials under the name pharmakognosie was first developed in German-speaking areas of Europe, while other language areas often used the older term materia medica taken from the works of Galen and Dioscorides. In German the term drogenkunde ("science of crude drugs") is also used synonymously.
As late as the beginning of the 20th century, the subject had developed mainly on the botanical side, being particularly concerned with the description and identification of drugs both in their whole state and in powder form. Such branches of pharmacognosy are still of fundamental importance, particularly for pharmacopoeial identification and quality control purposes, but rapid development in other areas has enormously expanded the subject. The advent of the 21st century brought a renaissance of pharmacognosy and its conventional botanical approach has been broadened up to molecular and metabolomic level.
Although most pharmacognostic studies focus on plants and medicines derived from plants, other types of organisms are also regarded as pharmacognostically interesting, in particular, various types of microbes (bacteria, fungi, etc.), and, recently, various marine organisms.
In addition to the previously mentioned definition, the American Society of Pharmacognosy also defines pharmacognosy as "the study of natural product molecules (typically secondary metabolites) that are useful for their medicinal, ecological, gustatory, or other functional properties." Other definitions are more encompassing, drawing on a broad spectrum of biological subjects, including botany, ethnobotany, marine biology, microbiology, herbal medicine, chemistry, biotechnology, phytochemistry, pharmacology, pharmaceutics, clinical pharmacy and pharmacy practice.
- medical ethnobotany: the study of the traditional use of plants for medicinal purposes;
- ethnopharmacology: the study of the pharmacological qualities of traditional medicinal substances;
- the study of phytotherapy (the medicinal use of plant extracts); and
- phytochemistry, the study of chemicals derived from plants (including the identification of new drug candidates derived from plant sources).
- zoopharmacognosy, the process by which animals self-medicate, by selecting and using plants, soils, and insects to treat and prevent disease.
- marine pharmacognosy, the study of chemicals derived from marine organisms.
At the 9th congress of Italian society of pharmacognosy it was stated that current return of phyto-therapy was clearly reflected by the increased market of such products. In 1998 the latest figures available for Europe, the total OTC market for herbal medicinal products reached a figure of $6 billion, with consumption for Germany of $2.5 billion, France $1.6 billion and Italy $600 million. In the US, where the use of herbal products has never been as prevalent as in continental Europe, the market for all herb sales reached a peak in 1998 of $700 billion. This welcomed the scientific investigation of a rigorous nature.
The plant kingdom still holds many species of plants containing substances of medicinal value which have yet to be discovered. Large numbers of plants are constantly being screened for their possible pharmacological value.