southern magnolia vs Magnolia grandiflora

southern magnolia and Magnolia grandiflora both are nouns.

Word	Noun	Adjective	Verb	Adverb
southern magnolia	Yes	No	No	No
Magnolia grandiflora	Yes	No	No	No

As nouns, southern magnolia and Magnolia grandiflora are synonyms defined as:

southern magnolia and Magnolia grandiflora: evergreen tree of southern United States having large stiff glossy leaves and huge white sweet-smelling flowers

Other synonyms of southern magnolia include bull bay, evergreen magnolia, large-flowering magnolia.

southern magnolia (noun)	Magnolia grandiflora (noun)
evergreen tree of southern United States having large stiff glossy leaves and huge white sweet-smelling flowers	evergreen tree of southern United States having large stiff glossy leaves and huge white sweet-smelling flowers