peachleaf willow vs willow tree

peachleaf willow and willow tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
peachleaf willow	Yes	No	No	No
willow tree	Yes	No	No	No

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

peachleaf willow: willow of the western United States with leaves like those of peach or almond trees
willow tree: any of numerous deciduous trees and shrubs of the genus Salix

Other hypernyms of peachleaf willow include willow.

peachleaf willow (noun)	willow tree (noun)
willow of the western United States with leaves like those of peach or almond trees	any of numerous deciduous trees and shrubs of the genus Salix