People – Krosnick Lab

Shawn Krosnick (she/her), PI

I am a systematic botanist who specializes in Passiflora, commonly known as passion flowers or passion fruit. My work is primarily focused on ways to better understand character evolution and homology assessment in taxonomic groups with complex morphology. I use traditional (anatomy and development), molecular (sequence comparison and gene expression), and ecological data (reproductive function) to answer questions about the evolution of pollination syndromes and plant mutualisms. Contact me at skrosnick@tntech.edu.

Current Students

Windsor Kiefer, Master’s student

I am studying the life history of Physaria globosa, a rare and endangered plant in the mustard family (Brassicaceae). This species is only found in a few locations in Tennessee, Kentucky and Indiana. We currently know very little about how long this species lives for. In Tennessee, it appears to function as a biennial, reproducing in the second year and dying. In Kentucky, there is some evidence that it may behave as a short-lived perennial. My work will examine phenotypic plasticity within populations and attempt to identify morphological characteristics associated with each stage of development. These data will then be used to generate life history matrices, or matrix population models, to help conservation workers better estimate population sustainability over time.

Stephanie Oliphant, Master’s student

My thesis research is focused on three reservoirs in the Tennessee River. First, I will conduct a floristic inventory of the aquatic and riparian plants in each area. Then, I will compare my inventory to the eDNA findings of another student who is working in the same locations. I will look for plant species found in the eDNA samples that are not found in my inventory and vice versa. Finally, I will carry out a historical analysis of the flora present before and after dam construction. My research will provide a contribution to the occurrences of native and non-native plant communities of the Tennessee River valley and a perspective on how damming changes the biodiversity of a river. It may also help reservoir managers make decisions regarding pesticide applications for the control of invasive aquatic species.

Emma Ralston, Undergraduate

I am assisting in the research of Physaria globosa, a federally endangered plant. I have assisted with germinating, planting, and completing morphometric analyses of this species. I am part of an undergraduate URECA TEAM grant from TN Tech looking at life history in this species.

Recent graduates

Chris Waters, Ph.D. student, graduated spring 2025. Chris is now an assistant professor at West Virginia Wesleyan College – congratulations Chris!

As an undergraduate student in Dr. Krosnick’s lab, Chris helped with research focused on the reproductive anatomy of Passiflora incarnata. I then moved to Kennesaw State University where I researched shifts in forest canopy composition in the montane longleaf pine ecosystems of northwest Georgia using dendrochronology and archival map data. For his Ph.D., he investigated the pollination ecology of a federally endangered mustard species called Physaria globosa as part of ongoing conservation efforts. We are classifying effective pollinator species and cataloging floral visitors across the range of P. globosa. Additionally, we are establishing a long-term monitoring protocol for these pollinator communities using environmental DNA left behind on flowers by potential pollinators.

Cassandra Fink, Master’s student, Graduated Fall 2024

Cassandra’s research focused on a species complex containing Lilium formosanum (Formosa Lily), Lilium philippinense (Benguet lily), and Lilium longiflorum (Easter lily). Taxa in this complex appear to be rapidly naturalizing across the Southeast and exhibit characters that could make them potentially invasive. However, it is unclear which species are present in the United States and whether they are hybridizing with one another as they spread. Her study focused on reproductive and floral phenology, pollination mechanisms, seed dispersal, and genetic relationships among this group in the United States.

Brittany McGuire, Master’s student, Graduated Fall 2022

Brittany’s research looked at how biology students understand experimental design both at the high school level and in introductory university courses. The primary objective her work was to determine how to better prepare students for futures in scientific fields. Her research interests are in science education, communication, and informal education. Brittany is now a teacher in Nashville!

Emily Powell, Master’s student, Graduated Fall 2022

Emily studied Physaria globosa, a Federally endangered species of Brassicaceae that is scattered throughout 31 populations in Tennessee, Kentucky, and Indiana. Her work focussed on the reproductive dynamics of this species to aid in its long-term survival.

Her specific goals were to determine the life history of P. globosa and assess pollen limitation. She did this through common garden studies with seed from each study site to monitor stage and age classes. Pollen limitation was also assessed through supplemental pollen treatments, which compared open/natural pollinated flowers to hand-pollinated flowers.

Eve Bolich-Sledge, Undergraduate student, Graduated Fall 2025

Eve helped with multiple projects, including Physaria field surveys, plant anatomy, tissue culture, and Lilium floral ecology and population genetics. She also served as a TA for Field Botany 3240. She is now working at UT Knoxville as a plant tissue culture technician at the Center for Agricultural Synthetic Biology.

Brittnay Carlile, Undergraduate student

Brittnay worked on a project that looked at host-plant feeding interactions in spittlebugs (Clastoptera spp.) and aphids (Aphis spp.) (Hemiptera). Both genera have specialized feeding stylets that allow for tapping into the xylem, phloem, or both. They secrete saliva that hardens to form an impervious and air-tight sheath for feeding. Brittnay is now a graduate student in the College of Education and plans to become a teacher!