creeping willow vs genus Salix

creeping willow and genus Salix both are nouns.

Word	Noun	Adjective	Verb	Adverb
creeping willow	Yes	No	No	No
genus Salix	Yes	No	No	No

creeping willow (noun)	genus Salix (noun)
small trailing bush of Europe and Asia having straggling branches with silky green leaves of which several varieties are cultivated	a large and widespread genus varying in size from small shrubs to large trees: willows