Cheilanthes bonariensis has been assigned to Notholaena in past treatments. It is distantly related (at best) to the species here included in Notholaena , however, and we concur with R. M. Tryon and A. F. Tryon (1982) that it should be transferred to Cheilanthes . Chromosomal studies (G. J. Gastony and M. D. Windham 1989) suggest that C . bonariensis is an apogamous triploid that arose through autopolyploidy. Further investigation is necessary to determine whether 64-spored, sexually reproducing populations of C . bonariensis are still extant.