The binomial Lobelia honors the French botanist Matthias de l'Obel.
The cardinal flower was one of the very first American plants to be shipped to Europe for cultivation.
There is a story the that new plant was presented to French queen Henrietta Maria, the wife of Anglican King Charles I. She was the teenaged daughter of King Henry IV of France and was Catholic which makes the next story make sense. The story continues that she sniggered because the color reminded her of the stockings and robes worn by Catholic cardinals.
Unfortunately Charles I was executed as the English Civil War broke out with Oliver Cromwell, a Puritan, heading the Protectorate. We colonists were without a king at this time with Puritans controlling the government. Queen Henrietta Maria fled home to France and returned to England only when her son, Charles II, was returned to the throne.
The cardinal flower contains the alkaloid lobeline, a powerful respiratory stimulant. It is used in the treatment of bronchitis and bronchial asthma.