This has been a very weird year. The weather is weird, the flowers are weird. We have iris blooming out of sequence and not looking as they normally would.
A chimera is caused by a mutation during development. What causes the mutations are several factors. In my research, I have found cold and herbicides to be the most common. Shape, size, petal count, color, form and height can all be affected.
Post your pictures here! Tell us what cultivar, if you know it, and why it's different.
I'll start with this NOID purple. We had a snow storm that caused these changes. Most flowers are normal but you can see several are not. They are paler, streaked and, in some cases, deformed.
These were the most affected.
Petal count was also different. This one has 2 falls, 2 standards and 2 style crests that are fused.
I. germanica also showed signs. It had 2 blooms like the above and the rest were mostly normal. This one, however, showed a color change.
Earl of Essex. Normally 35" tall had a stalk only 2". The flower was not affected.