Brassica vs genus Brassica

Brassica and genus Brassica both are nouns.

Word	Noun	Adjective	Verb	Adverb
Brassica	Yes	No	No	No
genus Brassica	Yes	No	No	No

As nouns, Brassica and genus Brassica are synonyms defined as:

Brassica and genus Brassica: mustards: cabbages, cauliflowers, turnips, etc.

Brassica (noun)	genus Brassica (noun)
mustards: cabbages, cauliflowers, turnips, etc.	mustards: cabbages, cauliflowers, turnips, etc.