This is not the finest example, but it is, never the less, lovely.
Some years this plant grows to be about 7' tall, with flowerheads up to 8" in diameter and looks very prehistoric and mysterious, but this year it has hovered just above my head, and not become very lush and full around the leafy bottom.
What you cannot tell from this photo, is that there are three bumble bees buzzing around in the "choke" the purple prickly part.
They look really remarkable in the purple fluff, but I couldn't get the proper angle to capture them, so you will just have to use your imagination and take my word for it.
The stalks of the cardoon are edible; peel and steam like celery (who steams celery? not me!)- very popular in Victorian times.
We have not, in our 19 years of growing cardoons, in three different houses, ever once peeled and steamed them.
We mostly just like them for looks, only, strictly ornamental.