black apricot vs apricot tree

black apricot and apricot tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
black apricot	Yes	No	No	No
apricot tree	Yes	No	No	No

As nouns, apricot tree is a hypernym of black apricot; that is, apricot tree is a word with a broader meaning than black apricot:

black apricot: small hybrid apricot of Asia and Asia Minor having purplish twigs and white flowers following by inferior purple fruit
apricot tree: Asian tree having clusters of usually white blossoms and edible fruit resembling the peach

Other hypernyms of black apricot include apricot.

black apricot (noun)	apricot tree (noun)
small hybrid apricot of Asia and Asia Minor having purplish twigs and white flowers following by inferior purple fruit	Asian tree having clusters of usually white blossoms and edible fruit resembling the peach