Pietra is a dark long-fermentation beer made with chestnut flour alongside the normal malt and hop mix, while Columba is a white wheat beer with herbal aromas based on the scent of the maquis.
Excellent stuff, and thank goodness for a supermarket that's willing to experiment.
However, I'm still looking forward to Whole Foods Market opening in London next year. The beer selection in the US stores is superb, and mainly micro-brewed stuff at very good prices. Here's hoping that they do the same over here.