Calla is a flowering genus of twenty-eight species. Calla lilies have long-petioled, basal leaves arising from a thick rhizome. The inflorescence, on a leafless flower stalk, consists of a spathe and spadix. The spathe, a large, flaring, trumpet-shaped bract, surrounds the spadix which is covered with tiny flowers. Calla lilies average between 1 and 3 feet high and have a diameter of approximately 1 to 1 and 1/2 feet when fully grown. The Calla lily leaves are 1 1/2' long, rich green. The green leaves of the calla lily are shaped like arrowheads and have white or silver speckles. Calla lilies are grown from bulbous roots with finger-like growths and are known as tubers.