Swamp rose is relatively distinctive. It grows in swamps. None of our other roses do that. Otherwise, swamp rose and all its relatives are a little tricky. When I first started identifying plants, it seemed they were all clearly different. And Roy Rogers always won. Turns out things aren't that simple. Careful keying of roses will most often lead to a correct identification, if it is a native rose. But there are hybrids that complicate the picture. And the introduced garden escapes are puzzles that may baffle anyone that can't sequence chromosomes. So, settle for a rose is a rose? Or visit swamps, where there can be only one. Swamp rose grows in AL, AR, CT, DE, FL, GA, IA, IL, IN, KY, LA, MA, MD, ME, MI, MO, MS, NC, NH, NJ, NY, OH, PA, RI, SC, TN, VA, VT, WI, WV, NB, NS, ON, and QC. Lenawee Co MI, 7/3/16.