common lettuce vs Lactuca sativa

common lettuce and Lactuca sativa both are nouns.

Word	Noun	Adjective	Verb	Adverb
common lettuce	Yes	No	No	No
Lactuca sativa	Yes	No	No	No

As nouns, common lettuce and Lactuca sativa are synonyms defined as:

common lettuce and Lactuca sativa: annual or perennial garden plant having succulent leaves used in salads; widely grown

Other synonyms of common lettuce include garden lettuce.

common lettuce (noun)	Lactuca sativa (noun)
annual or perennial garden plant having succulent leaves used in salads; widely grown	annual or perennial garden plant having succulent leaves used in salads; widely grown