Pronunciation: (kal'u),[key] —n. 1. Also called cal'la lil"y, arum lily. any of several plants belonging to the genus Zantedeschia, of the arum family, esp. Z. aethiopica, having arrow-shaped leaves and a large white spathe enclosing a yellow spike.
2. a related plant, Calla palustris, of cold marshes of Europe and North America, having heart-shaped leaves.