Ptilium De Notaris, 1867.

Ptilium is a monotypic genus widespread throughout moist forests in all northern North America and Eurasia. It has not yet been found in California. It is a genus segregated from Hypnum on the basis of its strongly plicate and decurrent leaves, and on the basis of a regularly pinnate and plumose branching pattern with the branches parallel and contiguous. The branches are strongly hamate at apices.
see key to Hypnum Etc.

Species included:
Ptilium crista-castrensis (Hedwig) De Notaris, not known from CA