black bearberry vs bearberry

black bearberry and bearberry both are nouns.

Word	Noun	Adjective	Verb	Adverb
black bearberry	Yes	No	No	No
bearberry	Yes	No	No	No

As nouns, bearberry is a hypernym of black bearberry; that is, bearberry is a word with a broader meaning than black bearberry:

black bearberry: deciduous creeping shrub bright red in autumn having black or blue-black berries; alpine and circumpolar
bearberry: chiefly evergreen subshrubs of northern to Arctic areas

black bearberry (noun)	bearberry (noun)
deciduous creeping shrub bright red in autumn having black or blue-black berries; alpine and circumpolar	chiefly evergreen subshrubs of northern to Arctic areas
	deciduous shrub of southeastern and central United States
	shrubby tree of the Pacific coast of the United States; yields cascara sagrada