sour cherry tree vs cherry tree

sour cherry tree and cherry tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
sour cherry tree	Yes	No	No	No
cherry tree	Yes	No	No	No

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

sour cherry tree: rather small Eurasian tree producing red to black acid edible fruit
cherry tree: any of numerous trees and shrubs producing a small fleshy round fruit with a single hard stone; many also produce a valuable hardwood

Other hypernyms of sour cherry tree include cherry.

sour cherry tree (noun)	cherry tree (noun)
rather small Eurasian tree producing red to black acid edible fruit	any of numerous trees and shrubs producing a small fleshy round fruit with a single hard stone; many also produce a valuable hardwood