Symphytum officinale vs comfrey

Symphytum officinale and comfrey both are nouns.

Word	Noun	Adjective	Verb	Adverb
Symphytum officinale	Yes	No	No	No
comfrey	Yes	No	No	No

As nouns, comfrey is a hypernym of Symphytum officinale; that is, comfrey is a word with a broader meaning than Symphytum officinale:

Symphytum officinale: European herb having small white, pink or purple flowers; naturalized as a weed in North America
comfrey: perennial herbs of Europe and Iran; make rapidly growing groundcover for shaded areas

Other hypernyms of Symphytum officinale include cumfrey.

Symphytum officinale (noun)	comfrey (noun)
European herb having small white, pink or purple flowers; naturalized as a weed in North America	leaves make a popular tisane; young leaves used in salads or cooked
	perennial herbs of Europe and Iran; make rapidly growing groundcover for shaded areas