mountain box vs red bearberry

mountain box and red bearberry both are nouns.

Word	Noun	Adjective	Verb	Adverb
mountain box	Yes	No	No	No
red bearberry	Yes	No	No	No

As nouns, mountain box and red bearberry are synonyms defined as:

mountain box and red bearberry: evergreen mat-forming shrub of North America and northern Eurasia having small white flowers and red berries; leaves turn red in autumn

mountain box (noun)	red bearberry (noun)
evergreen mat-forming shrub of North America and northern Eurasia having small white flowers and red berries; leaves turn red in autumn	evergreen mat-forming shrub of North America and northern Eurasia having small white flowers and red berries; leaves turn red in autumn