A cardoon is a vegetable, also known as the artichoke thistle, that looks a bit like celery on a bad day and has a flavor reminiscent of artichoke hearts and salsify.

Popular in Italy, Spain and France, the cardoon is related to the Globe artichoke. An invasive, frost-sensitive plant that needs a lot of space, the cardoon grows as a weed in the Argentine pampas, California and Australia.

Cardoons can be baked, braised or boiled, and it's often a good idea to blanch them for up to 30 minutes before using them. (Beware of sneaky thistles that may be lurking on the outer stalks -- it's best to peel the outside a bit.)

High in sodium, cardoons are nevertheless recognized as a good source of potassium, calcium and iron. Artichoke oil, which is similar to sunflower or safflower oil, can be extracted from cardoon seeds. It is currently being studied and tested for its biofuel potential.