This name is a synonym of Magnolia virginiana var. australis Sarg..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 117886) with original publication details: Kalmia 11: 2 1981.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:920041-1.
This name was in version 1 of The Plant List, record kew-117886, and has not been changed.