Biology

Yellow iris flowers from May to July (6); it reproduces by seeds as well as by vegetative reproduction (3). It is thought by some to be the origin of the 'fleur-de-lis' device used on coats of arms (4). In folk medicine, the rhizome of yellow iris was looked upon as something of a cure-all, being used to treat coughs, convulsions, toothache, diarrhoea, cramp, and as an antidote to poisoning (6). Furthermore, the flowers were used to produce a yellow dye, and the rhizome was used to make black dye (6).