I investigated phylogeography of Borrichia frutescens (bushy seaside tansy) in Florida. Phylogeography is the study of the geographic distribution of the genealogy of individuals. It is used to help understand how the changes in the landscape shaped the populations’ gene pool. Borrichia frutescens is a coastal salt marsh plant which occurs in Florida. I isolated a segment of the chloroplast DNA (cpDNA) in Borrichia frutescens. First, I obtained Borrichia frutescens from multiple locations in Florida. Next, I extracted DNA from leaves and perform a polymerase chain reaction (PCR) to amplify a segment of cpDNA; I will then determine the DNA sequence of the amplified segment. I will determine the evolutionary relationship among individuals. Then, I will compare their genetic variation to their geographic location along the coast line. I will compare the phylogeographic pattern of Borrichia frutescens to that of Spartina alterniflora, which is known. This experiment will show if the phylogeographic pattern of Borrichia frutescens follows the geological history of the state, leading to the prediction that the southern populations should be more recently established. Another prediction is that Borrichia frutescens follows a pattern where the populations in the peninsula differ from those in the panhandle.