black moss

from The Century Dictionary.

• noun The Spanish moss, Tillandsia usneoides, of the southern United States: so called from the black fiber that remains after the outer covering of the stem is removed. It is used as a substitute for horsehair in mattresses, etc.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun dense festoons of greenish-grey hairlike flexuous strands anchored to tree trunks and branches by sparse wiry roots; southeastern United States and West Indies to South America