It will be two years ago in August that I divided a large clump of gorgeous yellow iris and moved them to a 30 foot by 2 foot bed. Several tubers bloomed the folowing spring. Right smack in the middle of the brilliant yellow a bluish lavender iris appeared. MMMM! I thought, 'Where did that come from"? There are no other iris that I know about within miles of my home. This year I wake up one morning and there are bunches of bluish lavender flowers and no yellow yet. In the same spot where I had divided the original clump I have all yellow iris about to bloom. The original bed is probably no more than 30 feet away. What happened?