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Eric H. Roalson

Eric H. Roalson

Field of Study: Plant Systematics
Title: Professor
Degrees: Ph.D., Botany, Rancho Santa Ana Botanic Garden and The Claremont Graduate University
Homepage: Homepage/Lab Web Site Link
Google Scholar:  Google Scholar
Office: 339 Abelson Hall
Phone: 509-335-7921
Fax: nan
Mailing Address: School of Biological Sciences
Washington State University
PO Box 644236
Pullman,WA 99164-4236


Systematists and molecular phylogeneticists study the patterns and processes of organismal diversity, from the gene to the organism to the clade level, and ask questions focused on how the diversity we see has originated, and how different processes have led to these diversification patterns. Integration of studies across these different hierarchical levels is important to understand not only how lineages have diversified, and how they might be classified, but also what processes might have been important. My research has focused on two general questions: (1) what are the patterns of angiosperm diversity, from species boundaries to clade classifications to historical biogeography; and (2) what are the evolutionary dynamics of morphological and physiological traits (and their underlying genes) important to diversification, particularly floral structural changes and photosynthetic pathway modification. Current projects focus on the Cyperaceae, Gesneriaceae, Cleomaceae, and Chenopodiaceae, with studies exploring a variety of phylogenetic, cytogenetic, morphological, and physiological questions.

Representative Publications:

  • Bayat, S., E. Schranz, E. H. Roalson, and J. C. Hall. 2018. Lessons from Cleomaceae, the sister of crucifers. Trends in Plant Science 23(9): 808–821.
  • Roberts, W. R. and E. H. Roalson. 2018. Transcriptomic evidence of gene flow between species of magic flowers (Achimenes, Gesneriaceae). American Journal of Botany 105: 726–740.
  • Roalson, E. H. and J. C. Hall. 2017. New generic concepts for African Cleomaceae. Systematic Botany 42(4): 925–942.
  • Roberts, W. R. and E. H. Roalson. 2017. Comparative transcriptome analyses of flower development in four species of Achimenes (Gesneriaceae). BMC Genomics 18: 240.
  • Global Carex Group [P. Jiménez-Mejías, M. Hahn, K. Lueders, J. R. Starr, B. Brown, K.-S. Chung, M. Escudero, B. Ford, K. Ford, S. Gebauer, B. Gehrke, M. Hoffmann, J. Jung, S. Kim, M. Luceño, E. Maguilla, S. Martin-Bravo, M. Míguez, A. Molina, R. Naczi, A. A. Reznicek, T. Villaverde, M. J. Waterway, K. Wilson, J. Xiao-Feng, J.-C. Yang, S. Zhang, A. L. Hipp, and E. H. Roalson (P. Jiménez-Mejías, A. L. Hipp, and E. H. Roalson, communicating authors)]. 2016. Megaphylogenetic specimen-level approaches to the Carex (Cyperaceae) phylogeny using barcode regions ITS, ETS, and matK: systematics implications. Systematic Botany 41: 500–518.
  • Jiménez-Mejías, P., E. Martinetto, A. Momohara, S. Popova, S. Y. Smith, and E. H. Roalson. 2016. A commented synopsis of the pre-Pleistocene fossil record of Carex (Cyperaceae). The Botanical Review 82: 258–345.
    Roalson, E. H. and W. R. Roberts. 2016. Distinct processes drive diversification in different clades of Gesneriaceae. Systematic Biology 65: 662–684.
  • Rosnow, J. J., G. E. Edwards, and E. H. Roalson. 2014. Positive selection of Kranz and non-Kranz C4 phosphoenolpyruvate carboxylase amino acids in Suaedoideae (Chenopodiaceae). Journal of Experimental Botany 65: 3595–3607.
  • Hinchliff, C. E. and E. H. Roalson. 2013. Using supermatrices for phylogenetic inquiry: an example using the sedges. Systematic Biology 62: 205–219.
  • Clark, J. R., R. H. Ree, M. E. Alfaro, M. G. King, W. L. Wagner, and E. H. Roalson. 2008. A comparative study in ancestral range reconstruction methods: Retracing the uncertain histories of insular lineages. Systematic Biology 57: 693–707.