Phlebodium inaequale was treated as Polypodium pleurosorum Kunze ex Mett. by Mickel and Smith in the Pteridophytes of Mexico (Mem. NYBG 88, 2004). Daniel Tejero-Diaz, John Mickel, and Alan Smith later recognized it in Phlebodium in their 2009 paper describing a hybrid between it and Phlebodium pseudoaureum. They further support its position by citing unpublished DNA sequence data generated by H. Schneider. For further details see:

Tejero-DÍez, J. Daniel, John T. Mickel, and Alan R. Smith. “A hybrid Phlebodium (Polypodiaceae, Polypodiophyta) and its influence on the circumscription of the genus.” American Fern Journal 99.2 (2009): 109-116.