References

For Polypodium

Bryan, F.A., and D.E. Soltis. 1987. Electrophoretic evidence for allopolyploidy in the fern Polypodium virginianum. Systematic Bot. 12: 553-561. Google Scholar

Cusick, A.W. 2002. A binomial for the hybrid Polypodium of eastern North America. Amer. Fern J. 92: 240-241. Google Scholar

Haufler, C.H., M.D. Windham, F.A. Lang, and S.A. Whitmore. 1993. Polypodium. In Flora of North America Editorial Committee. 1993b. Flora of North America north of Mexico. Volume 2, pteridophytes and gymnosperms. Oxford Univ. Press, New York, NY. 475 pp. Google Scholar

Haufler, C.M., and M.D. Windham. 1991. New species of North American Cystopteris and Polypodium, with comments on their reticulate relationships. Amer. Fern J. 81: 7-23. Google Scholar

Haufler, C.M., M.D. Windham, and E.W. Rabe. 1995. Reticulate evolution in the Polypodium vulgare complex. Systematic Bot. 20: 89-109. Google Scholar

Hennipman, Veldhoen, & Kramer. 1990. In Kramer, K.U., and P.S. Green. 1990. Pteridophytes and Gymnosperms. In K. Kubitzki, ed., The families and genera of vascular plants. Springer-Verlag, Berlin. Google Scholar

Kott, L.S., and D.M. Britton. 1982. A comparative study of sporophyte morphology of three cytotypes of Polypodium virginianum in Ontario. Can. J. Bot. 60: 1360-1370. Google Scholar