Chance Riggins

Research Assistant Professor

 Dr. Riggins conducts interdisciplinary research in plant evolution, variation, and utilization. Agricultural weeds serve as exceptional models for much of Dr. Riggins' work, which advances fundamental knowledge on rapid evolution and adaptive responses in agricultural environments via unintentional human-mediated selection. As CEL Curator, Dr. Riggins is also a passionate advocate for agricultural biodiversity, traditional knowledge systems, conservation and sustainable use of plant genetic resources, and strengthening the link between "agri" and "culture".


  • Ph.D.: Plant Systematics, University of Illinois at Urbana-Champaign - 2008
  • M.S.: Phytochemistry, University of Alaska Fairbanks - 2001
  • B.S.: Forestry/Wildlife Management, Stephen F. Austin State University - 1995

Academic Positions

  • Research Assistant Professor, Department of Crop Sciences, University of Illinois (2014 - present)
  • Curator of the Crop Evolution Laboratory (CEL) Herbarium, Department of Crop Sciences, University of Illinois (2014 - present)
  • Postdoctoral Research Associate, Department of Crop Sciences, University of Illinois (2009-2013)

Research Interests

  • Adaptive evolution of agricultural weeds, mainly Amaranthus spp. (Amaranthaceae)
  • Plant Systematics
  • Economic Botany and Ethnobotany
  • Evolution and bioactivity of plant secondary compounds
  • Biological and Biocultural Curation

Honors, Recognition, and Outstanding Achievements for Research

  • Outstanding Paper Published in Weed Science, WSSA Annual Meeting - 2012
  • John R. Laughnan Award, Dept. of Plant Biology, UIUC - 2006
  • Herbert H. Ross Memorial Award, Illinois Natural History Survey - 2003
  • American Institute of Chemists Graduate Student Award, Univ. of Alaska Fairbanks - 2001

Honors, Recognition, and Outstanding Achievements for Teaching

  • Award for Outstanding Teaching, Dept. of Plant Biology, UIUC - 2007
  • List of Teachers Ranked as Excellent by their Students (multiple courses)

Books Edited or Co-Edited (Original Editions)

  • Eskinazi, D., Blumenthal, M., Farnsworth, N., and C. W. Riggins (eds). 1999. Botanical Medicine: Efficacy, Quality Assurance and Regulation. Mary Ann Liebert, Inc. Publ., NY.
  • Blumenthal, M., Grunwald, J., Hall, T., Riggins, C. W., and R. S. Rister (eds); Klein, S., Rister, R. S. (Trans.). 1997. German Commission E Monographs: Therapeutic Monographs of Medicinal Plants for Human Use. Austin, TX: American Botanical Council.
  • Blumenthal, M. and C. W. Riggins. 1997. Popular Herbs in the U.S. Market: Therapeutic Monographs. Austin, TX: American Botanical Council.

Selected Articles in Journals

  • Miller, J. T., Terra, V., Riggins, C. W., Ebinger, J. E., and D. S. Seigler. 2017. Molecular phylogenetics of Parasenegalia and Pseudosenegalia (Fabaceae:  Mimosoideae). Systematic Botany 42(3):465-469.
  • Evans Jr., A. F., O'Brien, S. R., Ma, R., Hager, A. G., Riggins, C. W., Lamber, K. N. and D. E. Riechers. 2017. Biochemical characterization of metabolism-based atrazine resistance in Amaranthus tuberculatus and identification of an expressed GST associated with resistance. Plant Biotech. Journal 15:1238-1249.
  • Seigler, D. S., Ebinger, J. E., Riggins, C. W., Terra, V. and J. T. Miller. 2017. Parasenegalia and Pseudosenegalia (Fabaceae: Mimosoideae): New genera of the Mimosoideae. Novon 25(2):180-205.
  • Huffman, J. L., Riggins, C. W., Steckel, L. E. and P. J. Tranel. 2015. The EPSPS Pro106Ser substitution solely accounts for glyphosate resistance in a goosegrass (Eleusine indica) population from Tennessee, United States. J. Integr. Ag. 15:1304-1312.
  • Schultz, J. L., Chatham, L. A., Riggins, C. W., Tranel, P. J. and K. W. Bradley. 2015. Distribution of herbicide resistances and molecular mechanisms conferring resistance in Missouri waterhemp (Amaranthus rudis Sauer) populations. Weed Sci. 63:336-345.
  • Guo, J., Riggins, C. W., Hausman, N. E., Hager, A. G., Riechers, D. E., Davis, A. S., and P. J. Tranel. 2015. Non-target-site resistance to ALS inhibitors in waterhemp (Amaranthus tuberculatus). Weed Sci. 63:399-407.
  • Chatham, L. A., Wu, C., Riggins, C. W., Hager, A. G., Young, B. G., Roskamp, G. K. and P. J. Tranel. 2015. EPSPS gene amplification is present in the majority of glyphosate-resistant Illinois waterhemp (Amaranthus tuberculatus) populations. Weed Tech. 29:48-55.
  • Délye, C., Duhoux, A., Pernin, F., Riggins, C. W., and P. J. Tranel. 2015. Research methods in weed science: molecular mechanisms of herbicide resistance. Weed Sci. 63(sp1):91-115.
  • Ma, R., Kaundun, S. S., Tranel, P. J., Riggins, C. W., McGinness, D. L., Hager, A. G., Hawkes, T., McIndoe, E., and D. E. Riechers. 2013. Distinct detoxification mechanisms confer resistance to mesotrione and atrazine in a population of waterhemp (Amaranthus tuberculatus). Plant Physiol. 163:363-377.
  • Gaines, T. A., Wright, A. A., Molin, W. T., Lorentz, L., Riggins, C. W., Tranel, P. J., Beffa, R., Westra, P., and S. B. Powles. 2013. Identification of genetic elements associated with EPSPS gene amplification. PLoS ONE 8(6):e65819. doi:10.1371.
  • Riggins, C. W. 2012. Artemisia woodii (Asteraceae), a new rank for a narrow endemic of the Yukon Territory, Canada. Phytologia 94:301-304.
  • Riggins, C. W. and D. S. Seigler. 2012. The genus Artemisia L. (Asteraceae: Anthemideae) at a continental crossroads: molecular insights into migrations, disjunctions, and reticulations among Old and New World species from a Beringian perspective. Mol. Phylogenet. Evol. 64:471-490.
  • Riggins, C. W. and P. J. Tranel. 2012. Will the Amaranthus tuberculatus resistance mechanism to PPO-inhibiting herbicides evolve in other Amaranthus species? Int. J. Agron. doi:10.1155/2012/305764.
  • Thinglum, K. A., Riggins, C. W., Davis, A. S., Bradley, K. W., Al-Khatib, K., and P. J. Tranel. 2011. Wide distribution of the waterhemp (Amaranthus tuberculatus) deltaG210 PPX2 mutation, which confers resistance to PPO-inhibiting herbicides. Weed Sci. 59:22-27.
  • Tranel, P. J., Riggins, C. W., Bell, M. S., and A. G. Hager. 2011. Herbicide resistances in Amaranthus tuberculatus: A call for new options. J. Agric. Food Chem. 59:5808-5812.
  • Riggins, C. W., Peng, Y., Stewart Jr, C. N., and P. J. Tranel. 2010. Characterization of de novo transcriptome for waterhemp (Amaranthus tuberculatus) using GS-FLX 454 pyrosequencing and its application for studies of herbicide target-site genes. Pest Manag. Sci. 66:1042-1052. [see associated Commentary (66:1041)].
  • Peng, Y., Abercrombie, L. L. G., Yuan, J. S., Riggins, C. W., Sammons, R. D., Tranel, P. J., and C. N. Stewart Jr. 2010. Characterization of the horseweed (Conyza canadensis) transcriptome using GS-FLX 454 pyrosequencing and its application to enable expression analysis of candidate nontarget herbicide resistance genes. Pest Manag. Sci. 66:1053-1062.
  • Riggins, C. W. and T. P. Clausen. 2003. Root acetylenes from Artemisia arctica. Biochem. Syst. Ecol. 31:211-214.