Carol A. Wilson

Research Scientists, Rancho Santa Ana Botanic Garden
Research Associate Professor of Botany, Claremont Graduate University


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Research Interests

I currently have two major projects underway. The first is on the genus Iris, which is comprised of about 300 species mainly from arid, mountainous regions in the Northern Hemisphere. Iris flowers are insect pollinated with sepal and petal ornamentation, nectar and/or floral displays from highly branched inflorescences. Geophytic organs that serve as storage organs and sources for renewal growth have developed from stems, roots and leaves in the genus.

Major questions being addressed are:
1) evolutionary relationships within the genus;
2) geographic origin of the genus;
3) biogeographic exchanges between Asia and North America;
4) evolution of geophytic storage structures; and
5) development of sepal beards as pollinator guides. 

My second project is on the Loranthaceae, a flowering plant family of 75 genera and more than 1000 species that occur largely in the Southern Hemisphere. Three genera are terrestrial, root-parasitic trees and shrubs, while the remaining genera are aerial branch-parasitic shrubs. The family is considered a “keystone resource” because it is utilized by a wide array of organisms in forest and woodland ecosystems worldwide.

Several interrelated questions are being addressed within the family, including:
1) the evolutionary pathway to the aerial-parasitic habit;
2) evolutionary relationships between genera; and
3) evolution of the haustorial system by which the parasite attaches to and procures water and minerals from its host. 

These projects are focused on systematics and evolution, are field based and utilize my training in morphology and molecular systematics. Students who work with me should appreciate natural history and understand the scientific process. They should be anxious to use a number of research tools to explore evolutionary questions in systematics and/or morphology.

Other on-going collaborations in research

Pollination biology of Oncocyclus species (with Nicolas Vereecken, University of Brussels, Belgium)

Geographic patterns of rhizome development in subgenus Iris (with Maia Akhalkatsi, Georgian Academy of Sciences, Democratic Republic of Georgia)

Relationships among taxa in the Iris hartwegii species complex from the Sierras (with Erin Riggs, Hoyt Arboretum, Portland, OR)

Epiparasitism in the viscoid mistletoes (with Clyde L. Calvin, Rancho Santa Ana Botanic Garden, Claremont, CA)

Flower size and floral pigments in Iris (with Eric Imbert, Montpellier University, France)


Ph.D. Integrative Biology, University of California, Berkeley, 1996
M.S. Biology, Portland State University, Portland, OR, 1985
B.S. Biology, Portland State University, Portland, OR, 1981

Recent courses taught

BOT 412 Special Topics in Plant Systematics: Readings in Plant Morphology and Development
BOT 498 Independent Study: Leaf Development
Plant Systematics
Analytic Techniques in Systematics
Plant Morphology
Symmetry in Plants
Morphology of Fruits
Inflorescence Structure

Present and former graduate students

Diana Jolles, Ph.D. candidate
Jinyan Guo, Ph.D. candidate
Andrew Wheeler, Ph.D. candidate
Lisa Karst, Ph.D., 2007
Lila Frazer, M.S., 2002
Peter Levasseur, M.S., 2002
Erin Riggs, M.S., 2002
Jeff Beaman, M.S. 2002
Lynda Boyer, M.S., 2000


Wilson, C. A. In press (2012). Relationships of the Iris sister series Californicae and Sibiricae in North America and China. Signa 85.

Karst, L. D. and C. A. Wilson. In press (2012). Phylogenetic analyses of the genus Sisyrinchium based on chloroplast and nrDNA data. Systematic Botany 37(1).

Wilson, C. A. 2011. Taxonomic relationships of Pacific Coast Irises. Almanac 40: 5–9.

Schmid, R., C. L. Calvin, and C. A. Wilson. 2011. Haustorial system structure in Phoradendron californica confounds the current classification. Aliso 29: 13–20.

Wilson, C. A. 2011. Subgeneric classification in Iris re-examined using chloroplast sequence data. Taxon 60: 27–35.

Wilson, C. A. 2010. Genus Iris. In B. G. Baldwin, S. Boyd, B. J. Ertter, D. J. Keil, R. W. Patterson, T. J. Rosatti, and D. Wilken [eds.], The Jepson manual: higher plants of California. University of California Press, Berkeley, CA, USA (electronic).

Calvin, C. L. and C. A. Wilson. 2009. Epiparasitism in Phoradendron. Aliso 27: 1–12.

Wilson, C. A. 2009. Phylogenetic relationships among the recognized series in Iris section Limniris. Systematic Botany 34: 277–284.

Weibang, S., Chunyan, H., Gao, L. and C. A. Wilson. 2007. Genetic diversity of the rare Asian plant Trigonobalanus doichangensis (Fagaceae). Australian Journal of Botany 55: 10–17.

Wilson, C. A. and C. L. Calvin. 2006. An origin of aerial branch parasitism in the mistletoe family, Loranthaceae. American Journal of Botany 93: 787–796.

Wilson, C. A. 2006. Patterns of evolution in characters that define Iris subgenera and sections, pp. 425-433. In J.T. Columbus, E. A. Friar, J. M. Porter, L. M. Prince and M. G. Simpson [eds.], Monocots: Comparative Biology and Evolution (excluding Poales). Rancho Santa Ana Botanic Garden, Claremont, CA.

Calvin, C. L. and C. A. Wilson. 2006. Comparative morphology of epicortical roots in Old and New World Loranthaceae with reference to root types, origin, growth, branching patterns and potential for clonal growth. Flora 201: 51–64.

Wilson, C. A. and C. L. Calvin. 2006. Character divergences and convergences in canopy dwelling Loranthaceae. Botanical Journal of the Linnean Society 150: 101–114.

Downey, P. O. and C. A. Wilson. 2004. Muellerina flexialabastra (Loranthaceae), a new species of mistletoe from south-eastern Australia. Australian Systematic Botany 17(5): 441–445.

Wilson, C. A. 2004. Phylogeny of Iris based on chloroplast matK gene and trnK intron sequence data. Molecular Phylogenetics and Evolution. 33(2): 402–412.

Wilson, C. A. 2003. Phenetic and intervarietal crossing data support the recognition of Iris tenax var. gormanii (Iridaceae), a rare northwest endemic. Madroño 50: 15–20.

Wilson, C. A. and C. L. Calvin. 2003. Development, taxonomic significance and ecological role of the cuticular epithelium in the Santalales. IAWA Journal 24: 129–138.

Wilson, C. A. 2003. A phylogenetic analysis of Iris series Californicae based on ITS sequences of nuclear ribosomal DNA. Systematic Botany 28: 39–46.

Wilson, C. A. 2001. Floral stages, ovule development, and ovule and fruit success in Iris tenax, focusing on var. gormanii, a taxon with low seed set. American Journal of Botany 88: 2221–2231.

Calvin, C. L. and C. A. Wilson. 1998. Comparative morphology of haustorial systems in the African Loranthaceae, pp. 17–36. In R. Polhill and D. Wiens [eds], Mistletoes of Africa. Royal Botanical Garden, Kew, Richmond, Surrey, UK.

Wilson, C. A. 1998. A cladistic analysis of Iris series Californicae based on morphological data. Systematic Botany 23: 73–88.

Wilson, C. A. and C. L. Calvin. 1996. Anatomy of the dwarf mistletoe shoot system, pp. 95–111. In F. G. Hawksworth and D. Wiens [eds.], Dwarf Mistletoes: Biology, Pathology, and Systematics. USDA, FS, Washington, D.C.

Calvin, C. L. and C. A. Wilson. 1996. Endophytic system, pp. 113–122. In F. G. Hawksworth and D. Wiens [eds.], Dwarf Mistletoes: Biology, Pathology, and Systematics. USDA, FS, Washington, D.C.