Enormous rhubarb-like leaves rise from the ground on thick, thorny stalks. Often seen in large gardens and parks, particularly at the West Coast. A bold feature plant for the waterside. Large cone-like heads of green flowers appear in summer. Must have a mild-winter climate to survive outside, otherwise grow in tubs to winter indoors. Determined gardeners might build a four foot-square box in late fall, filled with dry leaves to give insulation in cold winter regions. Plants must have a constantly moist to wet soil. Best in cool-summer climates.