* In "A Midsummer Night's Dream," Titania describes Demetrius as "a canker-blossom" because of his unrequited love for Helena. Demetrius's love is seen as destructive and damaging to the harmony of the forest.
* In "Hamlet," Ophelia laments that her brother Laertes has been corrupted by the time he spends in France. She refers to this influence as "the canker of our nature," suggesting that negative external influences can corrupt and ruin a person's true nature.
* In "Henry IV, Part 1," Hotspur compares the traitorous nobleman, Henry Percy, to a cankered rose. He remarks that while Percy may superficially appear noble and virtuous, his treachery makes him inwardly diseased and dangerous.
Therefore, the term "canker-blossom" is often used metaphorically in Shakespeare's works to represent emotional distress, moral decay, or flaws that undermine character or harmony.