Navarrete & Ollgaard  indicated the presence of a “C” group within Dennstaedtia Bernh. that contains D. obtusifolia (Willd.) T. Moore, which is the type material of the genus Patania C. Presl and indicated that it could require taxonomic recognition. They also discussed the situation generated by other authors including D. cornuta (Kaulf.) Mett. and D. obtusifolia as synonyms for D. dissecta (Sw.) T. Moore and then separated them as valid species; however, they insist on mentioning variables within the mentioned species and indicated that other species could be included. As a result of this group’s review from Costa Rica, it was found that there are three easily distinguishable new species: D. axillaris A. Rojas, D. rectangularis A. Rojas and D. riparia A. Rojas. Also, D. cornuta is registered from Mexico and Guatemala, and D. sprucei T. Moore is registered from Costa Rica.
Rojas, A.F. (2000) The Fern Genus Dennstaedtia (Dennstaedtiaceae) in Ecuador; New Characters, New Species and New Combination. Nordic Journal of Botany, 20, 319-346. https://doi.org/10.1111/j.1756-1051.2000.tb00747.x
Moran, R.C. (1995) Dennstaedtia. In: Moran, R.C. and Riba, R., Eds., Flora Mesoamericana. Volumen 1. Psilotaceae a Salviniaceae, Universidad Nacional Autónoma de México. D. F., México, 150-163. http://www.mobot.org/mobot/tropicos/meso/homep_sp.htm
Thiers, B. (2016) [continuously updated] Index Herbariorum: A Global Directory of Public Herbaria and Associated Staff. New York Botanical Garden’s Virtual Herbarium. http://sweetgum.nybg.org/science/ih/