Salix discolor vs willow

Salix discolor and willow both are nouns.

Word	Noun	Adjective	Verb	Adverb
Salix discolor	Yes	No	No	No
willow	Yes	No	No	No

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

Salix discolor: small willow of eastern North America having greyish leaves and silky catkins that come before the leaves
willow: any of numerous deciduous trees and shrubs of the genus Salix

Other hypernyms of Salix discolor include willow tree.

Salix discolor (noun)	willow (noun)
small willow of eastern North America having greyish leaves and silky catkins that come before the leaves	a textile machine having a system of revolving spikes for opening and cleaning raw textile fibers
	any of numerous deciduous trees and shrubs of the genus Salix