Japanese plum vs Japanese plum

Japanese plum and Japanese plum both are nouns.

Word	Noun	Adjective	Verb	Adverb
Japanese plum	Yes	No	No	No
Japanese plum	Yes	No	No	No

Japanese plum (noun)	Japanese plum (noun)
yellow olive-sized semitropical fruit with a large free stone and relatively little flesh; used for jellies	yellow olive-sized semitropical fruit with a large free stone and relatively little flesh; used for jellies
small tree of China and Japan bearing large yellow to red plums usually somewhat inferior to European plums in flavor	small tree of China and Japan bearing large yellow to red plums usually somewhat inferior to European plums in flavor
evergreen tree of warm regions having fuzzy yellow olive-sized fruit with a large free stone; native to China and Japan	evergreen tree of warm regions having fuzzy yellow olive-sized fruit with a large free stone; native to China and Japan