Erica perspicua vs true heath

Erica perspicua and true heath both are nouns.

Word	Noun	Adjective	Verb	Adverb
Erica perspicua	Yes	No	No	No
true heath	Yes	No	No	No

As nouns, true heath is a hypernym of Erica perspicua; that is, true heath is a word with a broader meaning than Erica perspicua:

Erica perspicua: South African shrub grown for its profusion of white flowers
true heath: any plant of the genus Erica

Other hypernyms of Erica perspicua include erica.

Erica perspicua (noun)	true heath (noun)
South African shrub grown for its profusion of white flowers	any plant of the genus Erica