cotinus
From LSJ
Ποιητὴς, ὁπόταν ἐν τῷ τρίποδι τῆς Μούσης καθίζηται, τότε οὐκ ἔμφρων ἐστίν → Whenever a poet is seated on the Muses' tripod, he is not in his senses
cŏtĭnus: i, m.,
I a shrub that furnishes a purple color: Rhus cotinus, Linn.; Plin. 16, 18, 30, § 73.