In the past, the term "drug" meant anything that was able to heal. It could be vegetable, animal, mineral substances or incantations, spells, amulets, etc. The essential thing was to escape death. This led to the birth of numerous imaginative practices that only today can be said to have been almost completely abandoned. Speaking of plants,
the theory of "signatures" is well-known, which tied the plant’s medicinal effectiveness to its outward shape. Because it has lobed leaves with lower face a wine red, Hepatica nobilis was thought to be useful in treating the liver, and so on. Of course, under the congeries of multiform beliefs and information, "reason" gradually succeeded in understanding what could objectively be of use to the patient.
In the Mediterranean world, the oldest information on the use of plants as medicines is linked to the Egyptians, but the use of officinal herbs by the peoples of the Tigris and Euphrates, Indians, and the peoples of the Far East is also well documented.
The art of healing took shape in classical antiquity, in Greece. Hippocrates (5th cent. BC) was its main architect. From the Greek world the use of plant species in therapy passed to the Roman one, where herbal medicine was considered a science. Dioscorides (1st cent. A.D.) described 600 different medicinals, mostly from plants, in his “materia medica”.
The rizotomi, or root cutters, collected plants and were experts. However, in order to pass on their knowledge, there arose a need to have books in which the different species were illustrated, so they could be recognized. It is said that Crateva, physician to Mithridates VI of Pontus (2nd-1st sec. B.C.), was the first to portray these plants. He began to fill herbaria that, together with treatises, allowed knowledge to pass from the Middle Ages to the Renaissance. In Italy, the modern science of botany was developed. The first medicinal herb gardens were created at the universities in Pisa and Padua.
With the discovery of America, many new plants reached the old world, and the medical knowledge of the Aztecs and other Amerindians was learned. The testing of new species increased and numerous miraculous plants appeared. Nicotiana tabacum seemed able to cure all ills.
However, the plants were also used in the kitchen. Since ancient times, numerous aromatic species were used in foods also as aperitifs, digestives, purgatives, etc. - the origin of modern nutraceuticals.
The volumes of information that, with the passage of time, have settled in the culture of nations now form a highly valuable heritage. It is from this that modern research has moved to determine what can truly be hidden in this atavistic work, to then be cast toward the current realities of science.