Rhizomes forming swollen storage tubers late in growing season. Leaf blade peltate, orbiculate, margins entire. Flowers exceeding leaves, to 2.5 dm or more diam.; tepals caducous or outermost persistent, 14-30, white to pink-purple or yellow; stamens 100-200. Fruits somewhat globose or ovoid; receptacle gradually or abruptly narrowed from top to base, base tapered to rounded, lateral surface striate or rugose. x = 8.