"Lily

The so-called Easter lily was once the floral emblem of the Goddess Juno in her virgin aspect, and of the spring Goddess who was her northern counterpart, Eostre, whose name gave us "Easter." Worshipers of  the Great Goddess insisted that the world's first lily sprang from the milk of her breast.1 Roman pagans said the lily sprang from Juno's milk; Roman Christians naturally reassigned the honor to the milk of Mary.(*)

The lily took over in Europe the role assigned to the lotus in Oriental sexual symbolism.2 That is, it became the female "cup" holding the divine essence of life. In fact, the Christian chalice (cup) was derived from the calyx (cup) of the lily flower. In the MIddle East, the lily was sacred to Astarte, who also bore the name of Lilith (the lily), from the Sumero-Babylonian lilu, a lotus.

The lily was always a symbol of the miraculous impregnation of the virgin Goddess. The "Blessed Virgin Juno" conceived Mars with it; so of course the Blessed Virgin Mary followed suit.

The difference between the pagan and Christian stories was that in the latter, the lily appeared in male hand, that of Gabriel, whose name means "divine husband."3

(*) Mary means "Beloved" in Egyptian.
1. Whittick, 265; Guthrie, 71. 
2.  d'Alviella, 102.
3. Whittick, 208."

The Woman's Dictionary of Symbols & Sacred Objects by Barbara G. Walker, p.428.

"Astarte (Astarat) Semitic goddess, associated manly with Syria and Palestine (Asthoreth). The Ugaritic form of her name is Attart; she appears in the Old Testiment as Asthoreth, (also as Lilith, "developed earliest in the Babylonian Talmud, who is generally thought to be in part derived from a class of female demons Līlīṯu in Mesopotamian texts of Assyria and Babylonia." "The legend was greatly developed during the Middle Ages, in the tradition of Aggadic midrashim, the Zohar, and Jewish mysticism.1) and in Babylon as Istar (Ishtar). Her cult was that of an oriental goddess of love and fertility, and was accordingly marked by many excesses (temple prostitution). She is usually shown naked. When she was taken over by the Egyptians she began to figure more and more as a goddess of war, and spear and bow were her attributes. Among the Greeks, Astarte was identified with Aphrodite as the heavenly goddess of love. As in the case of other fertility goddesses, her sacred creature was
dove. According to Philon of Byblos, she donned a bull's head as a symbol of her ruling position, and there are other references to the horns assigned to her."2

1. http://en.wikipedia.org/wiki/Lilith
2. The bull and ram horns adorned many ancient god during the Ages of Taurus and Aries respectively.

Dictionary of GODS and GODDESSES, DEVILS and DEMONS by Manfred Lurker, p.42.