Pedanius Dioscorides (c.29-90 AD) lived in the time of the notorious Roman Emperor Nero and is believed to have traveled widely with his armies, which gave him an opportunity to study and collect a wide variety of medicinal plants. Born in the town of Anazarbius, in what now is southern Turkey close to the Syrian border, he studied medicine at Tarsus and wrote a famous pharmacopeia of medicinal plants that remained a classical textbook for many centuries. It was called in its Latin version De Materia, the forerunner of modern encyclopedias, and was also translated into Arabic and more recently into modern languages.

The work was in five volumes and covered the preparation, properties, and therapeutic uses of substances obtained from animals, oils, trees, and minerals. He discusses milk, honey, and metals such as mercury, arsenic, lead, calcium, and copper; and described some 600 plants. The encyclopedia contains about one thousand drugs which he is said to have tested each clinically and then organized into therapeutic groups based on their action. He notably described cannabis, colchicum, peppermint, and hemlock, and reviewed drugs able to cause sleep and relieve pain such as opium and mandragora.