A fossil leaf fragment collected decades ago on a Virginia canal bank has been identified as one of North America's oldest flowering plants, a 115- to 125-million-year-old species new to science. The fossil find, an ancient relative of today's bleeding hearts, poses a new question in the study of plant evolution: did Earth's dominant group of flowering plants evolve along with its distinctive pollen? Or did pollen come later?

The find also unearths a forgotten chapter in Civil War history reminiscent of the film "Twelve Years a Slave." In 1864 Union Army troops forced a group of freed slaves into involuntary labor, digging a canal along the James River at Dutch Gap, Virginia. The captive freedmen's shovels exposed the oldest flowering plant fossil beds in North America, where the new plant species was ultimately found.

University of Maryland doctoral student Nathan Jud, a paleobotanist – an expert in plant fossils and their environments – identified the species and its significance. Jud named it Potomacapnos apeleutheron - Potomacapnos for the Potomac River region where it was found, and apeleutheron, the Greek word for freedmen. A paper describing the new species was published in the December 2013 issue of the American Journal of Botany.