Giant perennial for constantly moist locales near ponds, streams. Creeping rhizomes give rise to big (212 feet-wide), round leaves on edible, 3 feet-long stalks that are used by the Japanese as a vegetable (called fuki). Short, thick spikes of fragrant white daisies appear in early spring before the leaves emerge. Locate this plant with care; it has thick, invasive rhizomes and can be difficult to eradicate. P. j. giganteus has leaves to 4 feet wide on 5 feet stalks. Its selection 'Variegatus', with 3- to 4 feet stalks, has 2- to 3 feet-wide leaves with bold white markings.