Ballota nigra vs black archangel

Ballota nigra and black archangel both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ballota nigra	Yes	No	No	No
black archangel	Yes	No	No	No

As nouns, Ballota nigra and black archangel are synonyms defined as:

Ballota nigra and black archangel: ill-smelling European herb with rugose leaves and whorls of dark purple flowers

Other synonyms of Ballota nigra include black horehound, fetid horehound, stinking horehound.

Ballota nigra (noun)	black archangel (noun)
ill-smelling European herb with rugose leaves and whorls of dark purple flowers	ill-smelling European herb with rugose leaves and whorls of dark purple flowers