This name is a synonym of Clematis fremontii S.Watson.
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Ann. Missouri Bot. Gard. 30: 40 1943.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:60356-2.
This name was in version 1 of The Plant List, record kew-2726015, and has not been changed.