Lobelia cardinalis

Cardinal Flower is a spectacular show along the edge of a pond or water garden and is a great butterfly attractor with bright red flowers. Chocolate Truffle, or Black Truffle, forms attractive, bushy upright plants with dramatic, dark chocolate-purple foliage and bold red flowers. The new leaves emerge nearly black and fade to a deep, iridescent maroon as the plant matures during the heat of the summer.
Cardinal flower requires moist soil. It can even tolerate flooding but not drought.