Here is what pineappleing looks like.
In This photo: My Hand is used as a background for you to see how the leaves of this fan swirl to look like a bromeliad, or "pineapple" top. It doesn't affect the rhizome below it, nor does it affect the whole clump. Not all fans will pineapple at the same time, (but I have had my whole two year old clump of BEVERLY SILLS do it, and then died after the rough winter that ensued that year.) NOTE: the hole in the whorl is not an iris borer hole! It was a peck-mark left from my Guinea Fowl when they went through the garden this morning during their "rounds." :-)
This photo above shows how only one fan in this clump is "partially pineappled".
These two photos above are sibling seedlings from a cross of SAMBUCA X CELEBRATION SONG.
This photo was taken at Francelle Edwards' garden in Arizona. I had a great time there earlier this month! (Thanks for your hospitality, Francelle!)
Again, the pineappleing is in part o the clump, not affecting every fan. For Francelle, this clump still produced stalks, as you can see in the photo. However, here in Michigan, I don't recall seeing stalks come from fans that "pineapple" on me. (I will keep watching those above seedlings, though.)
All Said . . .
The only garden of mine where I see pineappleing this year is where those seedlings are located. I believe that it was a lack or water combined with a lack of soil nutrients that caused the seedlings in photos 1 & 2 above to show the pineapple effect.
I hope this helps all interested in what "pineappleing" is. :-)
Oh, and Francelle mentioned that she does not consider it a deadly occurance. Her irises usually pull out of it, but I think I remember her mentioning that some cultivars will pineapple more than others.
President - Mio Irisarians
Zone 4 (and a half . . .J)