genus Salix vs florist's willow

genus Salix and florist's willow both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Salix	Yes	No	No	No
florist's willow	Yes	No	No	No

genus Salix (noun)	florist's willow (noun)
a large and widespread genus varying in size from small shrubs to large trees: willows	much-branched Old World willow having large catkins and relatively large broad leaves