Attempting an identification based strictly on leaf morphology suggested the
possibility of four different genera: Anogramma, Asplenium, Cystopteris, and
Pityrogramma, all of which include taxa known in the local fern flora. Laminae
that were once pinnate, with an acroscopic segment, pointed to a member of
the Aspleniaceae (Asplenium sessilifolium Desv.) or Cystopteridaceae (Cystopteris
fragilis (L.) Bernh.). The presence of non-clathrate rhizome scales
eliminated Asplenium, but the presence of multicellular hairs similar to those of Cystopteris supported the latter, as did the presence of toothed margins,
although Cystopteris fragilis has veins ending in a sinus rather than in a tooth.
A third possibility was a member of the Pteridaceae, either Anogramma
leptophylla (L.) Link or Pityrogramma chaerophylla (Desv.) Domin, but in both
these species the lamina is gradually reduced, and in the former, the rhizome
does not bear scales, but hairs; additionally, the latter has not yet been