Some linguists explain the etymology of the botanical name euphorbion as deriving from the Greek verb phiepsilonrhobetaomega ("nourish, feed"). But according to Pliny this plant was discovered in the Atlas Mountains by Juba II, King of Mauretania, and named after his personal physician, Euphorbos. This paper aims to give credence to Pliny's version. Indeed, Juba described the plant, its latex and its therapeutical applications in a now lost treatise On Euphorbion (piepsilonrhoí epsilonvphiorhobetaioupsilon), which can be reconstructed through Greek and Latin testimonies. This treatise was the beginning of a long standing success. Juba and Euphorbos were living at the time when Greek medicine invaded the Roman world, and they are both representative of this cultural change.