Christmas rose vs black hellebore

Christmas rose and black hellebore both are nouns.

Word	Noun	Adjective	Verb	Adverb
Christmas rose	Yes	No	No	No
black hellebore	Yes	No	No	No

As nouns, Christmas rose and black hellebore are synonyms defined as:

Christmas rose and black hellebore: European evergreen plant with white or purplish rose-like winter-blooming flowers

Other synonyms of Christmas rose include Helleborus niger, winter rose.

Christmas rose (noun)	black hellebore (noun)
European evergreen plant with white or purplish rose-like winter-blooming flowers	European evergreen plant with white or purplish rose-like winter-blooming flowers
	slightly hairy perennial having deep green leathery leaves and flowers that are ultimately purplish-green