Oenothera harringtonii, an annual in the Onagraceae (evening primrose) family, is endemic to south-central Colorado. O. harringtonii populations differ geographically in the composition of the floral fragrance they emit: northwest populations emit fragrance that contains linalool while southeast populations do not. My project seeks to determine to what extent the variation in linalool production in O. harringtonii has a genetic basis. My research questions are: 1) Are O. harringtonii floral traits heritable? 2) What are the differences in gene expression between populations of O. harringtonii that produce linalool and populations that do not?