As other answers have noted, the poem is rich in alliteration, assonance, simile, personification, and imagery. Other literary devices it uses are consonance and allusion.
Consonance occurs when consonants inside words in close proximity are repeated. Like alliteration, which is the repetition of consonants at the beginning of words placed close together, consonance creates a pleasing sense of rhythm. An example of consonance in this poem is the repeated "k" sound at the end of words in this line:
broke out of boxes hunting for chinks in the dark
Another example, in lines four and five, is the interior "l" sound that is repeated in "lolling," "obscenely," "mildewed," and "yellowed."
Allusion is making reference to other literary works in a text or to historical facts or events. When the speaker compares the "evil necks" of the trailing roots to snakes, the word "evil" tips us off to think of Satan disguised as a serpent in the Garden of Eden in the biblical book of Genesis, waiting to seduce...
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