showy sunflower vs Helianthus laetiflorus

showy sunflower and Helianthus laetiflorus both are nouns.

Word	Noun	Adjective	Verb	Adverb
showy sunflower	Yes	No	No	No
Helianthus laetiflorus	Yes	No	No	No

As nouns, showy sunflower and Helianthus laetiflorus are synonyms defined as:

showy sunflower and Helianthus laetiflorus: tall rough-leaved perennial with a few large flower heads; central United States

showy sunflower (noun)	Helianthus laetiflorus (noun)
tall rough-leaved perennial with a few large flower heads; central United States	tall rough-leaved perennial with a few large flower heads; central United States