Easter Lily: The flower commonly referred to as the Easter lily was brought to the United States in the 1880s from Bermuda. Although it was not originally associated with Easter, it was so named because it flowered around this time of year. Lilies in general were a symbol of purity in medieval iconography, and the Bible mentions them frequently as representative of beauty, perfection, and goodness.
Americans were quick to attribute symbolic value to the fact that this particular plant produced its impressive white flowers at a time that more or less coincided with the celebration of the resurrection of Christ. And because it grows from a bulb that is 'buried' and the 'reborn,' it serves as a perfect emblem of the death and rebirth of the Savior. With their trumpet-shaped blooms suggesting the angel Gabriel's horn, lilies herald both the coming of spring and the celebration of the greatest Christian feast. They can be seen decorating homes and churches throughout the Easter season. (168-69).
This source also includes information about customs and symbols associated with holidays across the world, including Bastile Day, Carnival, Chinese New Year, Feast of the Dead, Fourth of July, Ganesh Chaturthi, Gion Matsuri, Hola Maholla, Indra Jatra, Janmashtami, Miss America Pageant, Naadam, Pitra Paksa Festival, Plough Monday, Saturnalia, Tanabata, Teej, Ute Bear Dance, Vesak, Waso, Yaqui Easter Ceremony, and many, many more.
Holiday Symbols & Customs. 3rd Ed. Edited by Sue Ellen Thompson. Detroit, MI: Omnigraphics, 2003. Call number: GT3930.T48 2003.