Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ĭnŭla, ae, f. [ἑλένιον], elecampane, a plant (Inula helenium, Linn.), Plin. 19, 5, 29, § 91; Col. 11, 3, 35; Hor. S. 2, 2, 44; 2, 8, 51.