If you go to a bog at this time of year, you are apt to find a sea of white, cottony balls waving in the breezes. These are the seed heads of Cottongrass (Eriophorum sp.), which are actually not grasses but sedges. (In contrast to grasses, which have hollow stems, the stems of most sedges are solid and triangular.) The similarity of these heads to cotton gave this plant its common name.
Cottongrass grows in acidic wetlands and bogs. It tolerates cold weather well, and is found in the northern half of the U. S. as well as further north where it is food for migrating Caribou and Snow Geese on the tundra as well as Grizzly Bears and Ptarmigan.
The cottony seed plumes, which aid in the dispersal of Cottongrass seeds, are too short and brittle to be made into thread, but they have been used for pillow-stuffing, wound dressing and in the production of candle wicks and paper.