This name is a synonym of Sedum dendroideum subsp. monticola (Brandegee) R.T. Clausen.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 8902095) with original publication details: Univ. Calif. Publ. Bot. 6(19): 498 1919.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:231786-2.
This name was in version 1 of The Plant List, record tro-8902095, and has not been changed.