The speaker claims, in the first stanza, that when he refused to discuss his anger with his foe, his "wrath" and anger grew. He then says that he
water'd it in fears,
Night & morning with [his] tears:
And [he] sunned it with smiles,
And with soft deceitful wiles.
This is the poison tree of the title, the tree that grows a bright and beautiful apple. This tree is a metaphor , as it does not literally exist, but he compares his growing wrath to this poison tree in order to demonstrate how wrath and resentment, when unresolved, can become a truly destructive force. His wrath is fed by his willingness to deceive his enemy with his tears and smiles. A metaphor is a comparison of two unalike things where one thing is said to be the other. It is not literal—there is no actual poison tree—but it has figurative meaning: the poison tree is figurative only, representative of the speaker's wrath. The apple that it grows is likewise metaphorical; however, the apple's effect on the speaker's foe is...
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