Notholaena californica D.C. Eaton 1883

Introduction

This beautiful small fern occurs in northern Mexico (Baja California Norte and Sur, and Sonora) and extreme southwestern US (Arizona and California). It is usually found in cracks in acidic rock cliffs and slopes, often in very dry exposed sites. I recognize two subspecies, based on Windham (1993a): N. californica ssp. californica (Yellow California Cloakfern) and N. californica ssp. leucophylla Windham (White California Cloakfern). These two taxa differ in the color of their farina (light to bright yellow, vs., bright white). This color difference is the result of significant differences in the chemical composition of the farina (Wollenweber, 1984).

The complete evolutionary history within N. californica, however, is complex. Notholaena californica ssp. californica is currently only known as an apogamous pentaploid (the sporophytes have five complete sets of chromosomes rather than the typical two sets, and produce unreduced spores, which develop into pentaploid gametophytes, which then produce a new sporophyte directly from their vegetative tissue, without sexual reproduction), based on a single chromosome count from a population in Arizona (Windham, 1993a). Notholaena californica ssp. leucophylla, on the other hand, has sexual diploid populations, apogamous triploid populations, and possibly tetraploid populations as well (Mickel and Smith, 2004). The relationship among these different populations (both within and between the subspecies) is in need of more study.

Characteristics

Notholaena californica is one of the core Notholaena species with strongly pentagonal leaves. As such it resembles N. standleyi or N. sulphurea, but its leaves are much more divided (almost lacey) than either of those two. Confusion is most likely with N. neglecta, which differs in its leaf shape (more elongate, almost deltate), its rhizome scales (strongly two-toned, with broad brown margins), and its range. Also, N. neglecta does not have a white chemotype; its farina are always yellow.

Other Names for Notholaena californica D.C. Eaton 1883

• Vernacular Names: California 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.