Any of several closely related species of the genus Lobelia , perennial plants of the lobelia family , native to North and Central America.
All bear spikes of scarlet, lipped flowers on leafy stems up to 5 ft (1.5 m) tall. L. cardinalis and L. splendens , considered to be one species by some authorities, are taller than L. fulgens , the Central American parent species of the garden cardinal flower. The blue cardinal ( L. siphilitica ) is smaller than the others and has blue or whitish flowers.