genus Salix vs Salix pentandra

genus Salix and Salix pentandra both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Salix	Yes	No	No	No
Salix pentandra	Yes	No	No	No

genus Salix (noun)	Salix pentandra (noun)
a large and widespread genus varying in size from small shrubs to large trees: willows	European willow tree with shining leathery leaves; widely naturalized in the eastern United States