Celtuce is a relative of the lettuce with thickened stems better known as celtuce. The leaves may be eaten either raw or cooked. Thick, tender. mild and sweet when young, though slightoy coarse, the leaves become bitter as they age. It is best to peel them before use, like celery. The flavour is variously described as being similar to any of artichoke, asparagus, lettuce or squash.