garden lettuce vs common lettuce

garden lettuce and common lettuce both are nouns.

Word	Noun	Adjective	Verb	Adverb
garden lettuce	Yes	No	No	No
common lettuce	Yes	No	No	No

As nouns, garden lettuce and common lettuce are synonyms defined as:

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

Other synonyms of garden lettuce include Lactuca sativa.

garden lettuce (noun)	common lettuce (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