bittersweet nightshade vs poisonous nightshade

bittersweet nightshade and poisonous nightshade both are nouns.

Word	Noun	Adjective	Verb	Adverb
bittersweet nightshade	Yes	No	No	No
poisonous nightshade	Yes	No	No	No

As nouns, bittersweet nightshade and poisonous nightshade are synonyms defined as:

bittersweet nightshade and poisonous nightshade: poisonous perennial Old World vine having violet flowers and oval coral-red berries; widespread weed in North America

Other synonyms of bittersweet nightshade include bittersweet, climbing nightshade, deadly nightshade, Solanum dulcamara, woody nightshade.

bittersweet nightshade (noun)	poisonous nightshade (noun)
poisonous perennial Old World vine having violet flowers and oval coral-red berries; widespread weed in North America	poisonous perennial Old World vine having violet flowers and oval coral-red berries; widespread weed in North America