Native to tropical America. Feathery roots; inflated stems set with floating, nearly circular leaves 125 inches wide. Showy, 2 inches flowers, carried many to a spike, are lilac-blue; upper petals have a yellow spot in center. Needs warmth to flower profusely. Where it is winter hardy, it can become an extremely serious, ineradicable pest; do not turn it loose in natural bodies of water.