Reed Grass (also known as Phragmites) is a "cosmopolitan" species, meaning that it occurs throughout the World. Although there is believed to be a non-agressive, naturally occurring variety of the plant here in Virginia, most of the occurences in the mid-Atlantic region of the US represent introductions.

This tall grass (sometimes 10 feet or more in height) can propogate itself very effectively by underground rhyzomes, often taking hold where marsh soils have been disrupted and creating vast, monocultural stands, that can outcompete all other wetland plant species. I like this picture with the tall power line tower in the background because, in all likelihood, it was the construction of this power line through the marsh that promoted the establishment of this particular colony of Reed Grass.