Iris pseudacorus seed pods

Found these odd seed pods on Kilmory Beach (Argyll, West Coast of Scotland) on Sunday. They look a bit like gherkins on the outside, but the inside looks a bit like corn (is that maize in British?) The outer skin was very hard and tough and had to be cut through with a knife.

 

Thank you to Martin Sanford (martinsanford on flickr) for the ID.

Done