|Aquatic plant, either annual or evergreen perennial with submerged stems. Leaves are kidney-shaped, deeply lobed, dark green, to 3 inches in length. Flowers are white with yellow centers, single, saucer-shaped, to 3/4 of an inch wide. Blooming occurs on the surface of water. Up to 250 species of this tuber or fiberous rooted perennial, but really only 2 widely available.