kingcup vs Caltha palustris

kingcup and Caltha palustris both are nouns.

Word	Noun	Adjective	Verb	Adverb
kingcup	Yes	No	No	No
Caltha palustris	Yes	No	No	No

As nouns, kingcup and Caltha palustris are synonyms defined as:

kingcup and Caltha palustris: swamp plant of Europe and North America having bright yellow flowers resembling buttercups

Other synonyms of kingcup include cowslip, marsh marigold, May blob, meadow bright, water dragon.

kingcup (noun)	Caltha palustris (noun)
any of various plants of the genus Ranunculus	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