Final answer:
"A Poison Tree" is falsely attributed to 'Songs of Innocence'; it actually belongs to William Blake's 'Songs of Experience', reflecting darker themes of human nature.
Step-by-step explanation:
"A Poison Tree" is not part of William Blake's Songs of Innocence; it is actually from "Songs of Experience". This poem explores themes of anger, resentment, and the consequences of suppressed emotions. Blake's Songs of Innocence and Songs of Experience are two distinct collections that juxtapose the innocent, pastoral world of childhood against a more adult, disillusioned view of the world. "A Poison Tree" fits into the latter category, emphasizing a darker perspective on human nature and interpersonal relationships.