Actaea rubra vs cohosh

Actaea rubra and cohosh both are nouns.

Word	Noun	Adjective	Verb	Adverb
Actaea rubra	Yes	No	No	No
cohosh	Yes	No	No	No

As nouns, cohosh is a hypernym of Actaea rubra; that is, cohosh is a word with a broader meaning than Actaea rubra:

Actaea rubra: North American perennial herb with alternately compound leaves and racemes of small white flowers followed by bright red oval poisonous berries
cohosh: a plant of the genus Actaea having acrid poisonous berries

Other hypernyms of Actaea rubra include baneberry, herb Christopher.

Actaea rubra (noun)	cohosh (noun)
North American perennial herb with alternately compound leaves and racemes of small white flowers followed by bright red oval poisonous berries	a plant of the genus Actaea having acrid poisonous berries