double gold vs Rudbeckia laciniata hortensia

double gold and Rudbeckia laciniata hortensia both are nouns.

Word	Noun	Adjective	Verb	Adverb
double gold	Yes	No	No	No
Rudbeckia laciniata hortensia	Yes	No	No	No

As nouns, double gold and Rudbeckia laciniata hortensia are synonyms defined as:

double gold and Rudbeckia laciniata hortensia: very tall branching herb with showy much-doubled yellow flower heads

Other synonyms of double gold include golden glow, hortensia.

double gold (noun)	Rudbeckia laciniata hortensia (noun)
very tall branching herb with showy much-doubled yellow flower heads	very tall branching herb with showy much-doubled yellow flower heads