Scirpus cyperinus, commonly known as woolgrass, is a herbaceous emergent that is native to the eastern United States and eastern Canada. Other common names include cottongrass bulrush and brown woolly sedge.This sedge is very variable in appearance. In general, it produces short, tough rhizomes and grows in dense clumps. The fertile stems grow upright. There are five to ten leaves per stem. They are up to 80 centimeters long by 1 centimeter wide. The proximal ones have green or reddish sheaths.