Phragmites. I love the word. Little bugs on Phraggle Rock? Nope. Phragmites are an invasive species of bamboo-like perennial grass more commonly known as the common reed. They are the tall, tall feathery topped things you see driving down the highway in marshy areas in the eastern US. They are spreading westward.
Phargmites totally take over disturbed areas of land when conditions are right. The right condition is wet...wet and disturbed. Highways through marshes. They are kind of pretty, in a monolithic sort of way.
They were/are used for their grain like seed, as a source of sugar, and all parts of the plant are edible while young. Other uses include thatching, fiber, mats, fuel, paper making, basketry, light weight shelters, the making of quill-like pens, and in a limited way as forage... somewhere in the world, not here. Here, modern commercial application is rare, perhaps non-existant.
The big problem with phragmites is they crowd out all the other cool marsh plants and are of very limited use as fodder for wetland wildlife. They spread mostly by runners and set very little seed. They fall over and create impenetrable physical barriers even when dead. They crowd out the sun and eliminate nesting sites for waterfowl. They are also a fire hazard. Yeah, marshes can burn.
Phragmites australis occur all over North America and are native here although there is growing evidence that the more invasive stands have a genetic background from an import. Increases in the problematic nature of the native genotype are also attributed to changes in land use.
http://www.scs.leeds.ac.uk/pfaf/index.html (very cool site)