Belladonna is an Italian word that translates to “beautiful lady,” and is a flower also called “deadly nightshade.” In art and literature, the belladonna flower is often symbolic of unsuspecting danger or false appearances due to its beautiful flowers but lethal berries. Not only the novel's title, belladonna is a symbol referenced frequently throughout the plot. Signa eats belladonna berries knowing they should kill her, allowing her to interact with Death in the space between life and death.

Although she does not always need the berries to use her powers, Signa often uses belladonna to amplify her powers or to be sure her powers will work, such as when she takes a large dose to sneak around Thorn Grove unnoticed. Her use of belladonna to contact death is what allows Signa to recognize the taste of the poison in Blythe’s tea and learn Lillian’s cause of death. In this case, the titular symbol of Belladonna not only represents the berries’ power over life and death, but also the hidden danger often associated with belladonna. Much like Signa and Percy, the two characters who utilize belladonna, the flower is much more dangerous than it looks. Additionally, the feminine connotations of the flower’s name also point to the underlying themes of gender throughout the text, gesturing toward how beautiful women can be much more powerful than they might appear in the eyes of society.