This name is a synonym of Crassula rupestris subsp. marnieriana (Huber & Jacobsen) Toelken.
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Cactus (Paris) 31(Suppl.): 8 1952.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:273280-1.
This name was in version 1 of The Plant List, record kew-2741879, and has not been changed.