A sharp or needle-like perennial herb grass up to 4.5 ft. that is found in tidal marshes on the banks of rivers and brackish waterways. Forms very dense colonies that often appear dark gray, silver, green or "black" from a distance. Tall grass often mats to one side. Can pierce clothing and human skin causing minor skin infections. Spreads vegetatively and to a lesser extent by very small seeds every few years in late Spring to Summer. Excellent for bank stabilization. Habitat for gators, birds, snails, insects and other wetland wildlife. Zones 7+.