Bladder Campion, Silene vulgaris, is so named because of the bladder like pods that the flowers pop out of. They sort of remind me of Alien eggs.
The pods are made up of fused sepals known as a calyx. They are native to Europe and the young leaves can be eaten in salads, whereas the stems can be chopped up and used in risottos. It also seems to be a good nectar provider for moths as well as a food source for their larvae.
Apparently it is also a Norwegian folk remedy for constipation. This seems preferable to the other Norwegian remedy of eating mouse droppings.