Thanks zipcode!
We did have an exceptionally horrible spring although it wasn't especially humid. Don't think the N was in excess but nutrient balance could be out of whack due to pH or other characteristics of the mix, so maybe that does explain it!
It reminded me of those mornings when you just don't want to wake up even though it's daylight, so you just squinch your eyes shut as tight as you can.
It makes sense from a biological standpoint that the cells along the sepal separation lines could be "sticky" until they get a cue that the flower is mature, time to open, and then stop making whatever protein or thing it is that keeps them together and protecting the bud.
And for some reason maybe an imbalance towards N, did not get the unsticky cue!
Sure is wierd looking.