American turkey oak vs oak tree

American turkey oak and oak tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
American turkey oak	Yes	No	No	No
oak tree	Yes	No	No	No

As nouns, oak tree is a hypernym of American turkey oak; that is, oak tree is a word with a broader meaning than American turkey oak:

American turkey oak: small slow-growing deciduous shrubby tree of dry sandy barrens of southeastern United States having leaves with bristle-tipped lobes resembling turkey's toes
oak tree: a deciduous tree of the genus Quercus; has acorns and lobed leaves

Other hypernyms of American turkey oak include oak.

American turkey oak (noun)	oak tree (noun)
small slow-growing deciduous shrubby tree of dry sandy barrens of southeastern United States having leaves with bristle-tipped lobes resembling turkey's toes	a deciduous tree of the genus Quercus; has acorns and lobed leaves