holy thistle vs Silybum marianum

holy thistle and Silybum marianum both are nouns.

Word	Noun	Adjective	Verb	Adverb
holy thistle	Yes	No	No	No
Silybum marianum	Yes	No	No	No

As nouns, holy thistle and Silybum marianum are synonyms defined as:

holy thistle and Silybum marianum: tall Old World biennial thistle with large clasping white-blotched leaves and purple flower heads; naturalized in California and South America

Other synonyms of holy thistle include blessed thistle, lady's thistle, milk thistle, Our Lady's mild thistle.

holy thistle (noun)	Silybum marianum (noun)
tall Old World biennial thistle with large clasping white-blotched leaves and purple flower heads; naturalized in California and South America	tall Old World biennial thistle with large clasping white-blotched leaves and purple flower heads; naturalized in California and South America