common marigold vs pot marigold

common marigold and pot marigold both are nouns.

Word	Noun	Adjective	Verb	Adverb
common marigold	Yes	No	No	No
pot marigold	Yes	No	No	No

As nouns, common marigold and pot marigold are synonyms defined as:

Other synonyms of common marigold include Calendula officinalis, ruddles, Scotch marigold.

common marigold (noun)	pot marigold (noun)
the common European annual marigold	the common European annual marigold