I've had the same experience for the past two years...i was thinking it might be because I stepped on top of them while they were still under the ground?!...i had to get back to the area of the garden where the trilium were and the jacks weren't up yet...when they came up a while later, they came out with the same wrinkly, bumpy texture you describe.

A few of mine exhibit the same behaior. I think it is a fungus.

There is a rust disease the name of which I can't think of at the moment which can infect all arisaema species. It is present in the native populations but is not lethal to them. Asian species, however, can be killed by it if it spreads to them from native stands.

What mainegrower said. Uromyces aritriphylli is a rust that can make the leaves look pretty bad and senesce early. Check the undersides for the telltale orange color. Unfortunately it can't be eradicated. Removing the infected leaves is supposed to help keep it from spreading but I've had no real luck.