This name is a synonym of Plectranthus rutenbergianus Vatke.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 192890) with original publication details: Adansonia n.s., 15: 524 1976.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:459179-1.
This name was in version 1 of The Plant List, record kew-192890, and has not been changed.