As cookiecrumb points out, it's pretty cool that my readers so quickly ID'd this photograph as artichoke stems. Thanks to all who responded!
It seems to be all the rage right now to sell globe artichokes with a foot of their stem still on - they were everywhere! A good friend told me she'd purchased some and had been instructed to keep the stems on and cook them in the oven in a large pan of water with sliced lemons, covered with foil. The results of this were disappointing. Not only did they take hours to cook, they browned unattractively, and only tasted OK.
Having jumped on the bandwagon and purchased my own artichoke and stem, I decided to pick the brain of a local Italian chef. He instucted me to remove the stem, peel it, and boil it and warned me that the stems would take a lot longer to cook that the artichoke. I boiled my enormous artichoke in my soup pan with lemon wedges, with the sliced stem thrown into the water. The stems indeed took quite a good 30 minutes extra cooking.
The outer part of the stem is too fibrous to use, but the inner part is really quite good. Circumstances led me to keep my cooked stems in the fridge too long to really use, but my guiding chef told me the interior of the stem makes a good salad.
I'd love to hear how other's cook the stems and what they use them for. Please leave your guidance/ideas in the comments!