European cities differ from their American counterparts in the way that urban vegetation is distributed, understood, and utilized. The tidy categories of planned versus unplanned or native versus invasive are often blurred by the dynamics of historical, political, and ecological change. We propose to explore this condition at the scale of the Roman streetscape. A historically significant street such as the Via Del Corso will serve as both subject and transect. As we move along it on foot from one end of the city to the other, we will pass through a variety of physical and notional boundaries, neighborhoods, political jurisdictions, and historical sites. We will explore, collect, catalogue, and analyze all vegetation encountered—from the lowly weed to the iconic ornamental. In a city that has always aspired to offer the impression (and promise) of unchanging permanence, we hope to demonstrate a dynamic system of ecology taking place right underfoot and overhead.