This name is a synonym of Magnolia mediocris (Dandy) Figlar.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 126758) with original publication details: J. Bot. 66: 47 1928.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:554996-1.
This name was in version 1 of The Plant List, record kew-126758.