I'll try for changing to a botanical thread.
I participated in a similar study for the plant commonly known as Spanish Moss. The botanist was attempting to use the same tecnique to locate the point of origin (center of growth) for the plant and collected samples of genetic material all along its range.
My part was to find and collect specimens of Spanish Moss from the northernmost outpost of the range. I located the point in First Landing State Park located on the southern edge of the Chesapeke Bay as it enters the Atlantic. This is also known as Cape Henry.
Strangely believe it, but the Bromeliad known as Spanish Moss is one of the most successful plants in the Western Hemisphere. It definitely has the largest range. Its range extends continuously from Virginia to Southern Argentina and some off shore islands in between
Wow. A subject I am interested in, too. I live about halfway between Montgomery and Auburn, Alabama. I work in Montgomery. There is Spanish moss in Montgomery, but not 25 miles North of Montgomery where I live. As I drive to work I am constantly looking for new outbreaks of Spanish moss. It sees to end at the Tallapossa river, but only where it flows West/East. At the other side of its big bend, where the flow is North/South, no Spanish moss.