sweet gum vs American sweet gum

sweet gum and American sweet gum both are nouns.

Word	Noun	Adjective	Verb	Adverb
sweet gum	Yes	No	No	No
American sweet gum	Yes	No	No	No

As nouns, sweet gum and American sweet gum are synonyms defined as:

sweet gum and American sweet gum: a North American tree of the genus Liquidambar having prickly spherical fruit clusters and fragrant sap

Other synonyms of sweet gum include bilsted, Liquidambar styraciflua, red gum, sweet gum tree.

sweet gum (noun)	American sweet gum (noun)
a North American tree of the genus Liquidambar having prickly spherical fruit clusters and fragrant sap	a North American tree of the genus Liquidambar having prickly spherical fruit clusters and fragrant sap
aromatic exudate from the sweet gum tree
reddish-brown wood and lumber from heartwood of the sweet gum tree used to make furniture