Birdnest

Lennard knew well every nook, crevice, and shelf of the quarry; on many a day in boyhood he had birdnested among the gorse that fringed its mouth, or fished for minnows and "pow-wowets" with a luggie and string in the slimy pool at the bottom; […]

As currently produced, this type of fiber is entangled, or birdnested, and resembles cotton (except for the color).