Jonathan O.C. Kubesch*, Kelly Winklelpleck*, Connor Doyle*, Lindsey Barbini*, John H. Fike*, and Michael Johnson**

*Virginia Tech School of Plant and Environmental Sciences

**Clarks River National Wildlife Refuge

Summary

Buffalo clover (Trifolium reflexum) is a true native clover of eastern U.S. provenance. Previous research suggests that buffalo clover has seed yields and weights similar to introduced clover species (making it suitable for increase). However, such research is limited, with little comparison of plant material from across the northern range of the species. In fact, there is overrepresentation of southern accessions from Georgia, Texas, Mississippi, and Florida. This overrepresentation stems from historical seed collections coming from Coastal Plain collections. In order to better represent accessions from the northern range of the species (both in current research and for future studies), this project sought to 1) conduct a comparison of buffalo clover accessions from across the range against red clover (T. pretense); and 2) bank seed from the Clarks River population for use in conservation and research. Plants were grown from seed to seed and studied in a common garden experiment with efforts taken to maintain genetic purity. Seed was then banked with the Southeastern Grasslands Initiative. Variability in phenotypes across the lifecycle were observed among northern and southern buffalo clover accessions, which suggests that the species complex has further structural variance. Southern accessions required less time to bloom and flowered without vernalization. Clarks River plant material has not yet flowered and appears to require vernalization.

Introduction

The native clovers of eastern North America are relics of the complex mosaic landscapes present prior to European settlement (Gillett and Taylor, 2001). Of these species, buffalo clover is an annual to biennial species with known morphological and reproductive variability (Vincent, 2001).

Kentucky clover (T. kentuckiense) is a recent addition to the flora (Chapel and Vincent, 2013). Species delimitation between Kentucky and buffalo clover has been determined using primarily floral characteristics; however, vegetative characters in a common garden experiment might further resolve the relationships within the species complex.

Previous work with Kentucky clover and running buffalo clover in greenhouse and field research suggest that these native species face fewer propagation challenges in comparison to other rare plants (Kubesch, 2018; Kubesch 2020). Historically, Dr. Norman Taylor at the University of Kentucky maintained all 3 clovers native to Kentucky in greenhouse collections (Kubesch, 2018; Daniel Boone, personal communication).

The objectives of this project were to collect seed from the northern edge of the buffalo clover range and compare buffalo to Kentucky clover. It was hypothesized that Kentucky clover would be more morphologically similar to buffalo clover accessions from Kentucky and Ohio than to accessions from the Coastal Plain.