Oreon, pen. prod. Herba. Plin. Simpliciter montanum signisicat. Plinius sic cognominat genus quoddam Polygoni fœmine. An hear be growing on hils, of some called Sāguinaria.
Lewis and Short: Latin dictionary
ŏrēon or ŏrīon, i, n., = o)/reion, a mountain-plant, a kind of polygonos, Plin. 27, 12, 91, 115