I think belladonnas are toxic plants and that is why they are also called "Deadly nightshade"!
Belladonna is one of the most toxic plants found in the Western hemisphere. Children have been poisoned by eating as few as three berries. Ingestion of a leaf of the Belladonna can be fatal to an adult[citation needed]. The root of the plant is generally the most toxic par, though this can vary from one specimen to another.

Maybe you're talking about another kind of Belladonna huh?