Big shaggy-moss is a large, loosely spreading leafy moss, which has pale green leaves pointing in different directions. The shoots of the sprouts are reddish and irregularly branched.

The species is an indicator for mature grove-like heath forests. It thrives also in damp groves and often grows next to Aspen trees. Its range extends to the temperate and cool areas of the Northern Hemisphere.

The big shaggy-moss, as its name suggests, has a shaggy appearance and resembles a furious cat's fluffy tail with raised fur. Despite its appearance, it spreads beautifully on the forest floor and is a common species of magnificent old forests.

The big shaggy-moss enters to the forest floor in later stages of forest rotation cycle. Having diverse forest age structure in a landscape level provides continously suitable habitats for different forest inhabiting species.