Pythius, A Lydian, dwelling at a towne in Phrygia called Celene, who had such aboundaunce of Gold, that he receyued Xerxes king of Persia, with all his whole armie, which was innumerable, and that with great magnificence: and offred moreouer, to giue treasure as well for prouiston, as also for wages, to haue had his sonne discharged of the warres, whiche Xerxes taking displeasauntlye, caused the youg man in his fathers sight to be cut in sunder. This man gaue also vnto Darius, father to Xerxes, a plane tree of Golde, & a vine of the same mettal: pet he taking thought for his sonne, inclosed himselfe in a sepulcher, which hee let make, and there finished his life miserably, and in extreme sorrow.
Lewis and Short: Latin dictionary
pthĭon, ĭi, n., = puqi/wn,a kind of bulbous plant, otherwise unknown, Plin 19, 5, 30, 95 (the correct reading is opitiona).