This name is a synonym of Magnolia fraseri var. pyramidata (Bartram) Pamp..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 19300214) with original publication details: Fl. N. Amer. 1(1): 43 1838.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:149291-2.
This name was in version 1 of The Plant List, record tro-19300214.