The meaning and etymology of the adjective apiosus

The author discusses the etymology and meaning of the adjective apiosus, which occurs in Pelagon. 405 (ad equum appiosum) and 406; Chiron 17, 257, 260, 276, 278, 279-280, 333, 986; Veg. mulom. 1.25.2; 2.2; 2.5.1, 2.9.3, 2.10, 2.11.1, 2.97.4 (all Vegetius’s passages depend on the Mulomedicina Chironis) and in Greek transliteration in Hipp. Cant. 81 (tit.) (ἀπιώσσου). The equus apiosus has staring eyes, pokes his head into the manger, cannot stand, and falls down if he tries to walk; sometimes he turns round and round as if pushing a millstone. The etymology of the word has previously been explained in terms of the curative (or magical) properties of the apium (‘celery’) (Ihm and Fischer), or of the sting of the apis (‘bee’) (Gourevitch) or a mistaken derivation from the Greek with confusion between σελινίτης (which should mean lunaticus, ‘epileptic’, but is not attested in this sense) and σελινίτης (from σέλινον = apium) (Magnani). In reality things are different. The word apiosus comes from apium agreste, or rusticum or risus, a poisonous plant which may be identified with Oenanthe crocata L. or Conium maculatum L. The term apiosus originally indicated an animal (in particular a donkey) which had eaten a large quantity of hemlock (Conium maculatum L.), a plant with intoxicating qualities (it is significantly named imbriága molèntis in some Sardinian dialects). Later the word apiosus came by analogy to designate an animal suffering from the disease now called Ryegrass staggers, caused by an endophytic fungus of the perennial ryegrass. An appendix on the gloss appiosus μετέωρος in the Hermeneumata Celtis (12.972) closes the study.