Spanish heath vs erica

Spanish heath and erica both are nouns.

Word	Noun	Adjective	Verb	Adverb
Spanish heath	Yes	No	No	No
erica	Yes	No	No	No

As nouns, erica is a hypernym of Spanish heath; that is, erica is a word with a broader meaning than Spanish heath:

Spanish heath: erect dense shrub native to western Iberian peninsula having profuse white or pink flowers; naturalized in southwestern England
erica: any plant of the genus Erica

Other hypernyms of Spanish heath include true heath.

Spanish heath (noun)	erica (noun)
erect dense shrub native to western Iberian peninsula having profuse white or pink flowers; naturalized in southwestern England	any plant of the genus Erica