Notholaena aureolina clade

Introduction

The N. aureolina clade is a rather disparate assemblage of species from Mexico and northern Central America that are typically bright yellow or orange farinose (three of four species) with well-developed false indusia (modified fertile leaf margins that curve over the sporangia). The farinose members (N. aureolina, N. jaliscana, and N. ochracea) have only recently been given names under Notholaena (Yatskievych and Arbeláez, 2008); historically, due to their well-developed false indusia, they were treated in Cheilanthes.

Characteristics

Notholaena aureolina and N. jaliscana are very likely to be sister species, although N. jaliscana has not been included in a phylogenetic study to date. They are both bright yellow-farinose with the bipinnate-pinnatifid leaf dissection typical of the core Notholaena, from which they differ in farina color and by possessing false indusia. Notholaena ochracea also has prominent false indusia, but has bright orange farina, and a tendency for its leaves to be less finely cut (becoming bluntly once-pinnate towards the tips). This leaf dissection is reminiscent of the last species in the clade, N. brachypus, which is consistently pinnate-pinnatifid. Notholaena brachypus, however, is not farinose. Its leaf undersides are instead covered with a dense layer of hairs and broad scales.

Discussion of Phylogenetic Relationships

The phylogenetic proximity of N. aureolina (under the name Cheilanthes aurea) and Notholaena/Cheiloplecton/Cheilanthes leucopoda has been resolved in several studies (Gastony and Rollo, 1995; Gastony and Rollo, 1998; Schuettpelz et al., 2007) but Rothfels et al. (2008) were the first to show that the N. aureolina clade is indeed a clade, is well-supported, and is nested within Notholaena s.s.

Other Names for Notholaena aureolina clade

• Vernacular Names: Yellow Cloakferns and allies, aleuritopteroid notholaenas, the aurantiaca/aurea/brachypus clade

References

Gastony, G. J., and D. R. Rollo. 1995. Phylogeny and generic circumscriptions of cheilanthoid ferns (Pteridaceae: Cheilanthoideae) inferred from rbcL nucleotide sequences. American Fern Journal 85:341-360.

Gastony, G. J., and D. R. Rollo. 1998. Cheilanthoid ferns (Pteridaceae: Cheilanthoideae) in the southwestern United States and adjacent Mexico--A molecular phylogenetic reassessment of generic lines. Aliso 17:131-144.

Mickel, J. T., and A. R. Smith. 2004. The Pteridophytes of Mexico. The New York Botanical Garden Press, New York.

Rothfels, C. J., M. D. Windham, A. L. Grusz, G. J. Gastony, and K. M. Pryer. 2008. Toward a monophyletic Notholaena (Pteridaceae): Resolving patterns of evolutionary convergence in xeric-adapted ferns Taxon 57:712-724.

Schuettpelz, E., H. Schneider, L. Huiet, M. D. Windham, and K. M. Pryer. 2007. A molecular phylogeny of the fern family Pteridaceae: assessing overall relationships and the affinities of previously unsampled genera. Molecular Phylogenetics and Evolution 44:1172-1185.

Tryon, R. M. 1956. A revision of the American species of Notholaena. Contributions from the Gray Herbarium 179:1-106.

Windham, M. D., L. Huiet, E. Schuettpelz, C. J. Rothfels, J. Beck, A. L. Grusz, G. Yatskievych, and K. M. Pryer. 2008. Using plastid and nuclear DNA sequences to redraw generic boundaries and demystify species complexes in cheilanthoid ferns. American Fern Journal (in review).

Yatskievych, G., and A. L. A. Arbeláez. 2008. A new species and three generic transfers in the fern genus Notholaena (Pteridaceae). Novon 18:120-124.