Chance Riggins

Research Assistant Professor

Dr. Riggins conducts interdisciplinary research on wild, weedy, and cultivated plants to understand adaptive evolution in natural and agricultural environments. Exploring plant uses and novel applications of plant natural products is another theme of his work. As curator of the Crop Evolution Lab Herbarium, which documents agricultural biodiversity, crop-wild relative genetic diversity, and allied biocultural knowledge, Dr. Riggins also passionately advocates for raising awareness of where our botanical products come from and why it matters.


  • 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, Crop Evolution Laboratory (CEL) Herbarium, University of Illinois (2014 - present)
  • Faculty Affiliate, Center for Latin American and Caribbean Studies, University of Illinois (2016-present)
  • Postdoctoral Research Associate, Department of Crop Sciences, University of Illinois (2009-2013)

Research Interests

  • Adaptive evolution of agricultural weeds; Amaranthus species
  • Crop-wild relative diversity and utilization
  • Industrial Hemp
  • 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

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

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

  • Riggins, C. W., Barba de la Rosa, A. P., Blair, M., and E. E. Rangel. 2021. Editorial: Amaranthus: Naturally Stress-Resistant Resources for Improved Agriculture and Human Health. Front. Plant Sci. 12:726875.
  • Riggins, C. W. and R. H. Mumm. 2021. Amaranth Quick Guide. Current Biology 31:R834-835.
  • Behnke, G. D., Kim, N., Zabaloy, M. C., Riggins, C. W., Rodriguez-Zas, S., and M. B. Villamil. 2021. Soil microbial indicators within rotations and tillage systems. Microorganisms 9(6):1244.
  • Kim, N. Zabaloy, M. C., Riggins, C. W., Rodriguez-Zas, S., and M. B. Villamil. 2020. Microbial shifts following five years of cover cropping and tillage practices in fertile agroecosystems. Microorganisms 8(11):1773.
  • Kim, N., Riggins, C. W., Rodriguez-Zas, S., Zabaloy, M. C., and M. B. Villamil. 2020. Long-term residue removal under tillage decreases amo-A nitrifiers and stimulates nirS-denitrifier groups in the soil. Appl. Soil Ecol. 157:103730.
  • Behnke, G. D., Zabaloy, M. C., Riggins, C. W., Rodriguez-Zas, S., Huang, L., and M. B. Villamil. 2020. Acidification in corn monocultures favor fungi, ammonia oxidizing bacteria, and nirK-denitrifier groups. Sci. Total Environ. 720:137514.
  • Leebens-Mack, J.H., Barker, M.S., Carpenter, E.J. et al. 2019. One thousand plant transcriptomes and the phylogenomics of green plants. Nature 574, 679-685. doi:10.1038/s41586-019-1693-2
  • Sun, R., Zhang, P., Riggins, C. W., Zabaloy, M. C., Rodriguez-Zas, S. and M. B. Villamil. 2019. Long-term N fertilization decreased diversity and altered the composition of soil bacterial and archaeal communities. Agronomy 9(10):574.
  • Huang, L., Riggins, C. W., Rodriguez-Zas, S., Zabaloy, M. C., and M. B. Villamil. 2019. Long-term N fertilization imbalances potential N acquisition and transformations by soil microbes. Sci. Total Environ. 691:562-571.
  • 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.
  • Crespo, R. J., Wingeyer, A. B., Kruger, G. R., Riggins, C. W., Tranel, P. J., and M. L. Bernards. 2017. Multiple-herbicide resistance in a 2,4-D-resistant waterhemp (Amaranthus tuberculatus) population from Nebraska. Weed Sci. 65(6):743-754.
  • 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.