I have seen this a couple of times in my garden.
The blooms look stunted.

Do you ever use roundup in the vacinity? I use roundup at the edges of my garden sometimes, and I've seen blooms similar. A small amount of roundup splatter doesn't kill the Iris, but does deform the blooms. The next year, without any further touches of roundup, they return to normal bloom.

It does look like chemical damage.

OHHHHH I expect that has something to do with it.
My daughter has put her foot down and I am no longer to be seen with the RU sprayer.
The garden doesnt matter to her but I dribble on the lawn.
Thanks for the info ,this will help two iris lovers.

With Round Up.....or even the 2,4 D type weed killers, you don't actually have to "hit" the plant with the spray , or even have " drift" carry the chemical to the plant.....if it's warm (I *think* the temp is 80 degrees for the 2,4,D, and slightly less for the 'round up" type veg killers) the "vapors" from the chemical is enough to affect the plant ! So, just using it in the *area*, can be enough to cause issues

I had some stunted blooms this year and my hubby swore he had not used any weed killer anywhere near my iris. Then I heard we had had a bad frost during a week we were gone when the iris were in bud. Subsequent buds on the stalk opened and were just fine, but the dried out buds either never bloomed or were deformed.

Arlyn, thanks for the tip.

I have had some deformed iris bloom on Black is Black. The flowers had standards but no falls, and I did use roundup near it, so that could be it I guess.

Another thing we need to consider, about "odd blooms", is , IMHO, that "first of the season", and "last of the season" blooms are very often "misshapen". It can be weather.....the start, may be "too cold", and the "end", "too hot "(or dry) , but I've noticed it, quite often, on many different cultivars