Berberis thunbergii vs barberry

Berberis thunbergii and barberry both are nouns.

Word	Noun	Adjective	Verb	Adverb
Berberis thunbergii	Yes	No	No	No
barberry	Yes	No	No	No

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

Berberis thunbergii: 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

Berberis thunbergii (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