Lobelia cardinalis A native U.S. wildflower that was so impressive to very early explorers that it was sent back to Europe and became widespread in European gardens by the 1600s. Named for the brilliant red of a cardinalís robe, the blooms are produced on tall stalks and are a natural source of nectar for hummingbirds. Cardinal Flowers prefer moist, rich soil. 3-4 feet. Part to most sun. Seeds should be planted in warm conditions. Perennial. 100+ seeds.