Lewis & Short

pūlĭcārĭus, a, um, and pūlĭcāris, e, adjj. [pulex], of or belonging to fleas, producing fleas, flea-bearing: herba, Cael. Aur. Acut. 2, 37, 197; 3, 8, 97.
Hence, subst.: pūlĭcārĭa, ae, f., a plant, called also psyllion, Theod. Prisc. p. 1, 10.