Common name...big beets. I tried some striped beets this year and they are very delicious and they don't turn your hands red. I only cooked the two largest ones and one turned white when it was cooked but tasted like a beet, very strange. I boiled for quite some time because they were so big, cooled them, peeled them, and then just tossed them in some olive oil and balsamic vinegar.
...And don't throw out those beet tops, they are fabulous sauteed in olive oil and garlic. I didn't take a picture because I ate them before I had the chance...but trust me...fabulous.