Tilia americana vs linden tree

Tilia americana and linden tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Tilia americana	Yes	No	No	No
linden tree	Yes	No	No	No

As nouns, linden tree is a hypernym of Tilia americana; that is, linden tree is a word with a broader meaning than Tilia americana:

Tilia americana: large American shade tree with large dark green leaves and rounded crown
linden tree: any of various deciduous trees of the genus Tilia with heart-shaped leaves and drooping cymose clusters of yellowish often fragrant flowers; several yield valuable timber

Other hypernyms of Tilia americana include basswood, lime, lime tree, linden.

Tilia americana (noun)	linden tree (noun)
large American shade tree with large dark green leaves and rounded crown	any of various deciduous trees of the genus Tilia with heart-shaped leaves and drooping cymose clusters of yellowish often fragrant flowers; several yield valuable timber