spinach vs Spinacia oleracea

spinach and Spinacia oleracea both are nouns.

Word	Noun	Adjective	Verb	Adverb
spinach	Yes	No	No	No
Spinacia oleracea	Yes	No	No	No

As nouns, spinach and Spinacia oleracea are synonyms defined as:

spinach and Spinacia oleracea: southwestern Asian plant widely cultivated for its succulent edible dark green leaves

Other synonyms of spinach include prickly-seeded spinach, spinach plant.

spinach (noun)	Spinacia oleracea (noun)
dark green leaves; eaten cooked or raw in salads	southwestern Asian plant widely cultivated for its succulent edible dark green leaves
southwestern Asian plant widely cultivated for its succulent edible dark green leaves