This plant has Long palm tree like leaves, found in a swampy area, and the boot looks yellow and white like a sugarcane.
sorry, I cannot help you with this grass. If you find it in flower, feel free to send me another image. By the habitat information, it could be Phragmites, but even that is not terribly likely. The leaves do not seem wide enough.
Dr. Steven Hill, Botanist SCNPS