Salix fragilis vs willow

Salix fragilis and willow both are nouns.

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

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

Salix fragilis: large willow tree with stiff branches that are easily broken
willow: any of numerous deciduous trees and shrubs of the genus Salix

Other hypernyms of Salix fragilis include willow tree.

Salix fragilis (noun)	willow (noun)
large willow tree with stiff branches that are easily broken	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