dirtdorphins said:Eek--dang virus!
I had no idea. Apparently, all my other patches of KH (which multiplies like mad here, and blooms consistently every year) are also streaky--just went back and looked at some pics I had from previous years. So yeah, they probably are all virused. These ones were a more recent acquisition and came with a bunch of mystery purples too; they came back like gangbusters!
do you see virus symptoms here as well?
So does this virus only effect bulbous iris? or will it/can it spread to other bulbs--like my tulips, crocus, etc., and can it be transmitted to bearded iris? or anything else?
When those annoying leaves shoot up here in the next bit--I can get my head around any excuse to vanquish them all 
It is hard to really see the fine details in the individual flowers in your last image. So it really is impossible for me to say for certain, but at this resolution I don't see any signs.
As far as I know, it isn't known what virus KH suffers from (or indeed if it really is a virus) so we can't really say what plants would be at risk of being infected. However, it is highly possible that other bulbous irises also would be at risk, so that was why I mentioned them specifically.
Plant viruses doesn't spread on their own, they need a little help, depending on the virus it could be sucking insects, nematodes, and not least the gardener. If you are just a little careful, I don't think you need to worry too much. Disinfect or wash cutting tools and hands frequently. Don't use your nails to dead head flowers, snap them off and be careful not to splash sap everywhere.
It is also important to remember that many, many plants carries viruses, without it causing them much harm. There are not always any visible signs either. Generally speaking the more viruses in a plant, the sicker it will get.
The first time I got virused tulips with broken colors I freaked out and discarded all of that cultivar. Today when I get a broken tulip I will simply remove it, its daughter bulbs and possible its closest neighbors.
One thing we can say is that if it is a virus, then KH still is vigorous enough to handle it, without it affecting growth too much.
Just beware of this potential problem and handle it anyway you are comfortable with.
