Geographic Variation in the Secondary Metabolites of Usnea strigosa

Nadja Seymour and Elizabeth A. McDonald

Chemotypes of the lichen species Usnea strigosa are well documented, and methods to identify common secondary metabolites are well established. However, geographic variation in secondary chemistry of this species has not been thoroughly investigated. In this study, we examined the presence of documented chemotypes in Upstate South Carolina and describe geographic variation in secondary metabolites both within and between collection sites. We discovered the absence of the most common chemotypes and found distinct chemical signatures that show geographic patterns with some compounds present only in specific locations and others common throughout the region.

• Nadja Seymour graduated from Ridge View High School in Columbia, SC. She is a senior biology major with a writing minor; Nadja plans to pursue graduate school for wildlife conservation and a career for the National Park Service.