Maidencane

[Swede]

Maidencane is part of a family of perennial grasses that are common but somewhat hard to tell apart. Maidencane can grow up to 8 feet tall and often forms dense colonies. It has long, narrowly tapered leaves(up to 12 inches long and 1 inch wide) with rough upper surfaces and margins. Flowers are on a long narrow spike (up to 12 inches long). Maidencane forms extensive rhizomes by which it spreads rapidly.

http://aquaplant.tamu.edu/database/emergent_plants/maidencane.htm