This name is a synonym of Homalothecium nuttallii (Wilson) A. Jaeger.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 35118589) with original publication details: Mem. Calif. Acad. Sci. 1: 32 1868.
This name was in version 1 of The Plant List, record tro-35118589.