[2] A variant on Rapunzel, Aarne–Thompson type 310, The Maiden in the Tower, it includes many motifs that differentiate it from that tale.
Other fairy tales of this type include Anthousa, Xanthousa, Chrisomalousa, Petrosinella, Prunella, and Rapunzel.
[3] A jealous stepmother persuades her husband, the king, to lock his daughter in a castle in the forest.
The princess escapes by cutting up her sheets for a rope, and overhears witches talking of things; one describes how to heal the prince.
In a review of Calvino's work, folklorist Walter Anderson classified the tale, according to the international Aarne-Thompson-Uther Index, as type AaTh 432, "The Prince as Bird".