red sorrel vs hibiscus

red sorrel and hibiscus both are nouns.

Word	Noun	Adjective	Verb	Adverb
red sorrel	Yes	No	No	No
hibiscus	Yes	No	No	No

As nouns, hibiscus is a hypernym of red sorrel; that is, hibiscus is a word with a broader meaning than red sorrel:

red sorrel: East Indian sparsely prickly annual herb or perennial subshrub widely cultivated for its fleshy calyxes used in tarts and jelly and for its bast fiber
hibiscus: any plant of the genus Hibiscus

red sorrel (noun)	hibiscus (noun)
East Indian sparsely prickly annual herb or perennial subshrub widely cultivated for its fleshy calyxes used in tarts and jelly and for its bast fiber	any plant of the genus Hibiscus