Publication: Werdenda. 1: 16. 1927.
selected vouchers: WTU
Notes: FNA2: "The diploid Polypodium amorphum is one of the progenitors of allotetraploid P . hesperium , and these two species are occasionally sympatric. Although P . amorphum can be mistaken for P . hesperium , consistent differences exist for separating these two species (see comments under P . hesperium ). Hybridization between P . amorphum and P . hesperium results in triploid individuals with misshapen spores (F. A. Lang 1971)."