References

For Azolla

Bates, V.M., and E.T. Browne. 1981. Azolla filiculoides new to the southeastern United States. Amer. Fern J. 71: 33-34. Google Scholar

Bunch, J., and W.J. Hayden. 2020. Noteworthy collections: Azolla filiculoides new to Virginia. Castanea 85: 229-231. Google Scholar

Evrard, C., and C. Van Hove. 2004. Taxonomy of the American Azolla species (Azollaceae): a critical review. Syst. & Geogr. Pl. 74: 301-318. Google Scholar

Lumpkin, T.A. 1993. Azollaceae. 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

Metzgar, J.S., H. Schneider, and K.M. Pryer. 2007. Phylogeny and divergence time estimates for the fern genus Azolla (Salviniaceae). Int. J. Plant Sci. 168: 1045-1053. Google Scholar

Reid, J.D., G.M. Plunkett, and G.A. Peters. 2006. Phylogenetic relationships in the heterosporous fern genus Azolla (Azollaceae) based on DNA sequence data from three noncoding regions. Int. J. Plant Sci. 167: 529-538. Google Scholar

Saunders, R.M.K., and K. Fowler. 1992. A morphological taxonomic revision of Azolla Lam. section Rhizosperma (Mey.) Mett. (Azollaceae). Bot. J. Linn. Soc. 109: 329-357. Google Scholar