brown cup vs sclerotinia

brown cup and sclerotinia both are nouns.

Word	Noun	Adjective	Verb	Adverb
brown cup	Yes	No	No	No
sclerotinia	Yes	No	No	No

As nouns, sclerotinia is a hypernym of brown cup; that is, sclerotinia is a word with a broader meaning than brown cup:

brown cup: a variety of sclerotinia
sclerotinia: any fungus of the genus Sclerotinia; some causing brown rot diseases in plants

brown cup (noun)	sclerotinia (noun)
a variety of sclerotinia	any fungus of the genus Sclerotinia; some causing brown rot diseases in plants