Lobelia :: Lobelia (n.) A genus of plants, including a great number of species. Lobelia inflata, or Indian tobacco, is an annual plant of North America, whose leaves contain a poisonous white viscid juice, of an acrid taste. It has often been used in medicine as an emetic, expectorant, etc. L. cardinalis is the cardinal flower, remarkable for the deep and vivid red color of its flowers..