Cattail

[Swede]

Cattails have flat to slightly rounded leaves that twist slightly over their length and can grow to 5 or 10 feet in height. Flowers form a dense dark brown, cigar-shape at the end of spikes (called the catkin). Cattails can be partially submerged or in boggy areas with no permanently standing water. Cattails spread rapidly because their seeds blow in the wind and float on the water's surface and vegetatively they spread from underground rhizomes.

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