In Ancient Greece, there existed a separation between physician and herbalist. The duties of the herbalist was to supply physicians with raw materials, including plants, to make medicines. According to Edward Kremers and Glenn Sonnedecker, "before, during and after the time of Hippocrates there was a group of experts in medicinal plants. Probably the most important representative of these rhizotomoi was Diocles of Carystus (4th century BC). He is considered to be the source for all Greek pharmacotherapeutic treatises between the time of Theophrastus and Dioscorides."
Between 60 and 78 AD, the Greek physician Pedanius Dioscorides wrote a five-volume book, De materia medica, covering over 600 plants and coining the term materia medica. It formed the basis for many medieval texts, and was built upon by many Middle Eastern scientists during the Islamic Golden Age.