Many of the most useful diagnostic characters for identifying the genera of Dennstaedtiaceae are found in the rhizome and lower petiole. In this case, the sulcate petiole base, the new rhizomes emerging from the petioles (epipetiolar buds), and the elongate stilt-roots, are diagnostic for Dennstaedtia. The study of these characters was pioneered by Hugo Navarette and Benjamin Øllgaard (2000) in their study of Ecuadorian species. Recently Triana et al. (2022) placed these  characters in a phylogenetic context and used them to diagnose clades.

Navarrete, H. and Øllgaard, B., 2000. The fern genus Dennstaedtia (Dennstaedtiaceae) in Ecuador,‐new characters, new species and a new combination. Nordic Journal of Botany, 20(3), pp.319-346.

Triana-Moreno, L.A., Yañez, A., Kuo, L.-Y., Rothfels, C.J., Pena, N.T., Schwartsburd, P.B. and Sundue, M. (2022), Phylogenetic revision of Dennstaedtioideae (Dennstaedtiaceae: Polypodiales) with description of Mucura, gen. nov.. TAXON. https://doi.org/10.1002/tax.12858