Rhus copallina vs sumac

Rhus copallina and sumac both are nouns.

Word	Noun	Adjective	Verb	Adverb
Rhus copallina	Yes	No	No	No
sumac	Yes	No	No	No

As nouns, sumac is a hypernym of Rhus copallina; that is, sumac is a word with a broader meaning than Rhus copallina:

Rhus copallina: common nonpoisonous shrub of eastern North America with compound leaves and green paniculate flowers followed by red berries
sumac: a shrub or tree of the genus Rhus (usually limited to the non-poisonous members of the genus)

Other hypernyms of Rhus copallina include shumac, sumach.

Rhus copallina (noun)	sumac (noun)
common nonpoisonous shrub of eastern North America with compound leaves and green paniculate flowers followed by red berries	a shrub or tree of the genus Rhus (usually limited to the non-poisonous members of the genus)
	wood of a sumac