Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† crătaeŏgŏnon, i, n., and crătaeŏgŏnŏs,, i, f., = κραταιόγονον, the common fleawort, Plin. 27, 8, 40, § 62 sq.