psyllion
Could not find psyllii in Logeion dictionaries.
psyllii Noun: neuter genitive singular of psyllion
psyllĭon, ĭi, n., = ψύλλιον,
- a plant, fleabane, fleawort, Plin. 25, 11, 90, § 140; Cael. Aur. Acut. 3, 8, 97.
psyllion, iī, n. (ψύλλιον), das Flöhkraut, rein lat. herba pulicaris u. pulicaria, Plin. 25, 140. Cael. Aur. de morb. acut. 3, 8, 97.
psyllĭon (-ĭum), ĭī, n. (ψύλλιον), plantain ou herbe aux puces : Plin. 25, 146.