Abstract
The systematics of the aquatic fern genusAzolla Lam. is revised at the supraspecific level. Published morphological data are reviewed, and cytological and cladistic analyses of the genus conducted, enabling a discussion of the putative evolutionary trends in the genus, and a revision of the current taxonomy. A phylogenetically more acceptable subgeneric and sectional classification is proposed, viz. subg.Azolla sect.Azolla (comprisingA. filiculoides Lam.,A. rubra R. Br.,A caroliniana auct. nonWilld.,A. microphylla auct. nonKaulf. andA. mexicana Presl), subg.Azolla sect.Rhizosperma (Mey.)Mett. (comprisingA. pinnata R. Br.), and subg.Tetrasporocarpia subg. nov. (comprisingA. nilotica Decne. exMett.).
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Saunders, R.M.K., Fowler, K. The supraspecific taxonomy and evolution of the fern genusAzolla (Azollaceae). Pl Syst Evol 184, 175–193 (1993). https://doi.org/10.1007/BF00937434
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DOI: https://doi.org/10.1007/BF00937434