References
For Cystopteris
Ekrt, L., J. Košnar, C.J. Rothfels, K. Hanušová, O. Hornych, and T. Urfus. 2022. Cytogenetic, geographical, spore type and plastid haplotype data reveal cryptic patterns of species diversity in the cosmopolitan Cystopteris fragilis complex (Polypodiopsida: Cystopteridaceae). Bot. J. Linn. Soc. Google Scholar
Haufler, C.H., R.C. Moran, and M.D. Windham. 1993. Cystopteris. 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., M.D. Windham, and T.A. Ranker. 1990. Biosystematic analysis of the Cystopteris tennesseensis (Dryopteridaceae) Complex. Ann. Missouri Bot. Gard. 77: 314-329. Google Scholar
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
Rothfels, C.J., A.K. Johnson, M.D. Windham, and K.M. Pryer. 2014. Low-copy nuclear data confirm rampant allopolyploidy in the Cystopteridaceae (Polypodiales). Taxon 63: 1026-1036. Google Scholar
Shmakov, A.I., A.A. Batkin, and A.V. Vaganov. 2018. Synopsis of the genus Cystopteris Bernh. (Cystopteridaceae) . Ukrainian J. Ecol. 8: 290-297. Google Scholar
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Windham, M.D., and K.M. Pryer. 2022. First report of Utah fragile fern (Cystopteris: Cystopteridaceae) from New Mexico, and new nomenclatural combinations in Cystopteris tennesseensis. J. Bot. Res. Inst. Texas 16(1): 1-7. Google Scholar