Japanese barberry vs barberry

Japanese barberry and barberry both are nouns.

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

As nouns, barberry is a hypernym of Japanese barberry; that is, barberry is a word with a broader meaning than Japanese barberry:

Japanese barberry: compact deciduous shrub having persistent red berries; widespread in cultivation especially for hedges
barberry: any of numerous plants of the genus Berberis having prickly stems and yellow flowers followed by small red berries

Japanese barberry (noun)	barberry (noun)
compact deciduous shrub having persistent red berries; widespread in cultivation especially for hedges	any of numerous plants of the genus Berberis having prickly stems and yellow flowers followed by small red berries