lady's thistle vs Silybum marianum

lady's thistle and Silybum marianum both are nouns.

Word	Noun	Adjective	Verb	Adverb
lady's thistle	Yes	No	No	No
Silybum marianum	Yes	No	No	No

As nouns, lady's thistle and Silybum marianum are synonyms defined as:

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

lady's 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