Notholaena lemmonii D.C. Eaton 1880

Introduction

This is a predominantly Mexican species of rocky open slopes, which barely extends into the United States in extreme southeastern Arizona (where it is rare—S1S2—NatureServe, 2008). There are two currently recognized varieties with non-overlapping geographic ranges, which probably represent distinct species. Further study is needed. Notholaena lemmonii var. lemmonii has dark leaf stalks, long rhizome scales, and occurs from the Mexican state of Jalisco north, whereas N. lemmonii var. australis R. M. Tryon has light stalks, shorter rhizome scales, and is found only in Michoacán, Guerrero, Oaxaca, and México (Mickel and Smith, 2004).

Notholaena lemmonii var. lemmonii is one of the notholaenid taxa that exhibits interesting variation in farina color and chemistry (Wollenweber, 1984). Most individuals have white or very pale yellow farina, but some plants, particularly from the islands of the Gulf of California, have deep orange farina. The taxonomic significance of these chemotypes warrants further attention.

The position of N. lemmonii within core Notholaena II (as inferred from plastid DNA sequences—Rothfels et al., 2008) is a little odd, given that it has long linear leaves, and thus superficially resembles the members of core Notholaena I. However, N. lemmonii is glabrous, while most member of core Notholaena I are scaly. It and the closely related N. meridionalis appear to represent a single independent transition to linear leaves (Rothfels unpublished).

Characteristics

Notholaena lemmonii is one of the strongly farinose linear-leaved core Notholaena taxa that cannot easily be confused with anything outside this group. Within the linear-leaved Notholaena, N. lemmonii is distinct from most (i.e., N. grayi and other members of core Notholaena I) by its glabrous leaves, and from the closely related N. meridionalis by its grooved leaf stalks (the leaf stalks of N. meridionalis are not grooved).

Other Names for Notholaena lemmonii D.C. Eaton 1880

• Notholaena lemmonii var. australis Tryon 1956
• Vernacular Names: Lemmon's Cloakfern

References

Giauque, M. F. A. 1949. Wax glands and prothallia. American Fern Journal 39:33-35.

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

NatureServe. 2008. NatureServe Explorer, Arlington, Virginia. www.natureserve.org/explorer/

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.

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

Windham, M. D. 1993a. Notholaena. Pages 143--149 in Flora of North America (Flora of North American Editorial Committee, ed.) Oxford University Press, New York.

Windham, M. D., and G. Yatskievych. 2003. Chromosome studies of cheilanthoid ferns (Pteridaceae: Cheilanthoideae) from the western United States and Mexico. American Journal of Botany 90:1788-1800.

Wollenweber, E. 1984. Exudate flavonoids of Mexican ferns as chemotaxonomic markers. Rev. Latinoamer. Quim. 15:3-11.