Notholaena R.Br., Prodr.

Kessler, Michael, Smith, Alan R. & Prado, Jefferson, 2017, Prodromus of a fern flora for Bolivia. XXVII. Pteridaceae, Phytotaxa 332 (3), pp. 201-250 : 215

Notholaena R.Br., Prodr. 145. 1810.

Notholaena is characterized by white or yellow powdery farina on the underside of the blades, sessile or adnate pinnae, sori borne at the vein tips, and a base chromosome number of x = 30. Argyrochosma differs by having stalked, entire, oblong ultimate segments, Aleuritopteris has strongly differentiated pseudoindusia, while Cheilanthes and Myriopteris have nonfarinose blades and sori restricted to and covered by the reflexed margins. Rothfels et al. (2008) explored the convergence of morphological characters in this and other xeric-adapted fern genera within Pteridaceae .

Notholaena comprises ca. 30 New World species, with 24 species in Mexico ( Mickel & Smith 2004), and 10 in southwestern U.S.A. ( Windham 1993). The genus name has often been applied to some Old World species with undifferentiated or poorly differentiated pseudoindusia, but these taxa are now included in other genera, particularly Allosorus , Paragymnopteris , and Cheilanthes . European authors, especially, have circumscribed Notholaena differently, relying on a different typification (for discussion, see Yatskievych & Smith 2003).

Notholaena is not monophyletic as currently described, but can probably be made monophyletic with the addition of the genus Cheiloplecton from Mexico and Central America, plus a few other predominantly Mexican species traditionally placed in Cheilanthes ( Rothfels et al. 2008, Yatskievych &Arbeláez 2008, Wang et al. 2015). Phylogenetic relationships were explored by Rothfels et al. (2008) and Johnson et al. (2012).