Wild Oats & Yellow Flag Irises ~ Iris pseudacorus. According to legend the first person to wear the Iris as a heraldic device was Clovis, who became king of the Franks in the late 5th century. He drove the Romans out of Northern Gaul, was converted to Christianity and changed the three toads on his banner for three yellow Irises. Six centuries later the Iris was adopted by Louis VII in the fleur-de-lys which he worn in his Crusade against the Saracens ? ?Lys? is a corruption of Louis. The Word Iris is Greek for Rainbow & the plants are grown in gardens for their showy flowers in various shades of yellow, violet, blue & white. Another name for the Yellow Iris is sword flag as it?s leaves are sharp edged & can cut if handled carelessly. Susan