The lily is the flower traditionally associated with the Virgin Mary in Christianity. More specifically, the white Madonna lily (Lilium candidum) became a Marian symbol of purity, chastity, and innocence.
Medieval and Renaissance artists frequently placed a white lily in scenes of the Annunciation, where the archangel Gabriel announces Christ’s birth to Mary. The flower’s whiteness and graceful form helped express Mary’s virginity and holiness. In Christian art, the lily can also represent the Holy Trinity because of its three-part structure.
The answer is sometimes confused with the rose, which is also a Marian symbol—especially the white rose, representing purity, or the mystical rose, a title associated with Mary. However, when a quiz asks for the flower most conventionally identified with the Virgin Mary, “lily” is the standard answer.
The fleur-de-lis is a stylized lily-like emblem that later acquired strong Marian and royal associations, although its precise botanical resemblance is debated.