cowslip vs marsh marigold

cowslip and marsh marigold both are nouns.

Word	Noun	Adjective	Verb	Adverb
cowslip	Yes	No	No	No
marsh marigold	Yes	No	No	No

As nouns, cowslip and marsh marigold are synonyms defined as:

cowslip and marsh marigold: swamp plant of Europe and North America having bright yellow flowers resembling buttercups

Other synonyms of cowslip include Caltha palustris, kingcup, May blob, meadow bright, water dragon.

cowslip (noun)	marsh marigold (noun)
early spring flower common in British isles having fragrant yellow or sometimes purple flowers	swamp plant of Europe and North America having bright yellow flowers resembling buttercups
swamp plant of Europe and North America having bright yellow flowers resembling buttercups