This name is a synonym of Plectranthus epilithicus B.J.Pollard.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 192887) with original publication details: J. Linn. Soc., Bot. 58: 272 1962.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:459176-1.
This name was in version 1 of The Plant List, record kew-192887, and has not been changed.