In Greek mythology, Iris was the daughter of Thaumas and the Ocean nymph Electra (according to Hesiod), the personification of the rainbow and messenger of the gods. As the rainbow unites Earth and heaven, Iris is the messenger of the gods to men; in this capacity she is mentioned frequently in the Iliad, but never in the Odyssey, where Hermes takes her place.
Iris is represented as a youthful virgin, with wings of gold, who hurries with the swiftness of the wind from one end of the world to the other, into the depths of the sea and the underworld. She is especially the messenger of Zeus and Hera, and is associated with Hermes, whose caduceus or staff she often holds. By command of Zeus she carries in an ewer water from the Styx, with which she puts to sleep all who perjure themselves. Her attributes are the caduceus and a vase.
The word iridescence is derived in part from the name of this goddess.