Dryopteris cristata is believed to be an allotetraploid derived from D . ludoviciana and an unknown diploid called " D . semicristata " by W. H. Wagner Jr. (1971). This ancestral taxon could have been either North American or Eurasian and may have become extinct during the last glaciation (T. J. Carlson and W. H. Wagner Jr. 1982). Dryopteris cristata hybridizes with five species; these hybrids can be identified by the narrow blades and deltate proximal pinnae.