sweet goldenrod vs goldenrod

sweet goldenrod and goldenrod both are nouns.

Word	Noun	Adjective	Verb	Adverb
sweet goldenrod	Yes	No	No	No
goldenrod	Yes	No	No	No

As nouns, goldenrod is a hypernym of sweet goldenrod; that is, goldenrod is a word with a broader meaning than sweet goldenrod:

sweet goldenrod: goldenrod of eastern America having aromatic leaves from which a medicinal tea is made
goldenrod: any of numerous chiefly summer-blooming and fall-blooming North American plants especially of the genus Solidago

sweet goldenrod (noun)	goldenrod (noun)
goldenrod of eastern America having aromatic leaves from which a medicinal tea is made	any of numerous chiefly summer-blooming and fall-blooming North American plants especially of the genus Solidago