What's wrong with this iris?

Is this a fungus or some other problem? I have several irises that look like this. Totally normal ones are right next to this one. How should I treat it? Or should I throw it away?

Any help is appreciated.

It may be something like pineappling. Last year some of my iris got kind of caught in their fans and the blooms were deformed and the leaves never developed right.
I didn't do anything for them...didn't know what to do, but this year they are growing OK.
Chances are it will be deformed for 2007.
But next year it will be all right.
No one knows what causes this, but it is not fatal. It may be frost or a virus. I am assuming it is not a weed killer like Roundup, but I would not rule that out.
If it bothers you, you can cut off the fan and it may grow a little better this year.
Laetitia
I

Thanks Laetitia.

There was no round up sprayed anywhere near these iris. :-) We have had some weird weather this year so that may be it. It is just strange because one will have it and the one right next to it (of the same cultivar) is perfectly normal. Some of these pineappled iris have even put up buds.