The Easter lily is a true species lily, classified as Division IX (not a hybrid or cultivar), native to Taiwan and the southern islands of Japan. In nature, they bloom in early to mid summer, but growers traditionally induce flowering around Easter, hence the name. Easter lilies are stem-rooting perennial bulbs that grow up to 1 metre (3 feet 3 inches) high, bearing long, dark green leaves and several fragrant, trumpet-shaped, white flowers. The plants require a cool period of at least 8 weeks below 18 degrees Centigrade (65 Fahrenheit) in order to bloom, and the yellow anther sacs of pollen should be removed to increase flower life and prevent staining of the petals. A taller and more vigorous variety of Easter lily from the Ryukyu Islands goes by the name Bermuda lily because it is cultivated extensively in Bermuda. All parts of the Easter lily are poisonous, especially to cats.