Rhamnus californicus vs California coffee

Rhamnus californicus and California coffee both are nouns.

Word	Noun	Adjective	Verb	Adverb
Rhamnus californicus	Yes	No	No	No
California coffee	Yes	No	No	No

As nouns, Rhamnus californicus and California coffee are synonyms defined as:

Rhamnus californicus and California coffee: evergreen shrub of western United States bearing small red or black fruits

Other synonyms of Rhamnus californicus include California buckthorn, coffeeberry.

Rhamnus californicus (noun)	California coffee (noun)
evergreen shrub of western United States bearing small red or black fruits	evergreen shrub of western United States bearing small red or black fruits