boysenberry vs western dewberry

boysenberry and western dewberry both are nouns.

Word	Noun	Adjective	Verb	Adverb
boysenberry	Yes	No	No	No
western dewberry	Yes	No	No	No

As nouns, western dewberry is a hypernym of boysenberry; that is, western dewberry is a word with a broader meaning than boysenberry:

boysenberry: cultivated hybrid bramble of California having large dark wine-red fruit with a flavor resembling raspberries
western dewberry: American blackberry with oblong black fruit

Other hypernyms of boysenberry include Rubus ursinus, western blackberry.

boysenberry (noun)	western dewberry (noun)
large raspberry-flavored fruit; cross between blackberries and raspberries	American blackberry with oblong black fruit
cultivated hybrid bramble of California having large dark wine-red fruit with a flavor resembling raspberries