C. bulbosum is a common and possibly one of the most recognizable moss in Tasmania. It occurs predominantly in wet forest to rainforest habitats, frequently as an epiphyte.

The elongated fronds are large by moss standards and may easily be mistaken for those of a small fern. 

The leaves are arranged in three ranks and in a single plane. The row of leaves on the shoot underside is reduced in size and is sometimes referred to as underleaves. The capsules are borne on the shoot underside.