Corona Australis was known to the Greeks not as a crown but as a wreath, which is how it is depicted on old star maps. Aratus did not name it as a separate constellation but referred to it as a circlet of stars beneath the forefeet of Sagittarius. Perhaps it has slipped off the archer’s head.
None of its stars is brighter than fourth magnitude and there seem to be no legends associated with it, unless this is the crown placed in the sky by Dionysus after retrieving his dead mother from the Underworld. Hyginus gives this myth under the Northern Crown (Corona Borealis) but it seems out of place there and he may have confused the two constellations. If so, the wreath would be made of myrtle leaves, for Dionysus left a gift of myrtle in Hades in return for his mother, and the followers of Dionysus wore crowns of myrtle.