Like many of the symbols Faulkner uses, the narcissus is deeply ambiguous in its implications. In Christian iconography, it is a symbol of renewal associated with the resurrection of Christ. Earlier Greek mythology, however, also allies it with death. Narcissi grow in abundance on the banks of the River Styx, across which the souls of the dead were transported to Hades. They are also sacred to Demeter, the harvest goddess who presides over the cycle of life and death, as well as to her daughter Persephone, the personification of spring-time renewal and goddess of the Underworld. Benjy’s flower, therefore, evokes the impermanence of hope and rejuvenation: like the sound and the fury to which the novel’s title refers, these too will ultimately be subsumed by their own destruction and come to signify nothing.
Carrying a narcissus to Quentin’s grave is highly apt, given the manner in which the mythological youth dies. Watch an amazing video recreation of Salvador Dali's 'Metamorphosis of Narcissus' showing his transformation into a flower.