Black Truffle Cardinal Flower. This new selection of our native Cardinal Flower has incredible deep burgundy foliage which holds throughout the season. In late summer and fall when it produces 3-4' spikes of brilliant red flowers, which makes it one of the best hummingbird attracters in the garden. This species grows in the wild in wet areas, so it will take more wet feet than most. But with adequate moisture, it does well on high ground as well.