E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
So called, according to fable, from Pæon, the physician who cured the wounds received by the gods in the Trojan war. The seeds were, at one time, worn round the neck as a charm against the powers of darkness. Virgil and Ovid speak of its sanative virtues. Others tell us Pæon was a chieftain who discovered the plant.
Vetustissima inventu pæonia est, nomenque auctoris retinet, quam quidam pentorobon appellant, alii glycysiden.Pliny, xxv. 10.