Iris comes from the Greek word for rainbow, perhaps because of the many colors of flowers in the species. (The Greek goddess of the rainbow is Iris)
It has been used in medicines and perfumes over the years and the fleur-de-lis, a stylized iris, which first occured in its modern use as the emblem of the House of Capet, is a featured emblem for many entities, including the New Orleans Saints. The Iris is the State flower of Tennessee and State Wild flower of Louisiana and Michigan.
Many famous artists, including my daughter, have featured them in paintings.