Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pōpŭlĭfer, ĕra, ĕrum, adj. [2. populusfero], poplar-bearing (poet.): Padus, whose banks abound with poplars, Ov. Am. 2, 17, 32: Spercheos, id. M. 1, 579.