You read it correctly - rattlesnake beans! They are so called because of their rattlesnake appearance - green and purple streaks. They can be cooked just as you would any other snap bean. I was surprised to find the taste the same as other fresh snap or pole beans.
To cook the beans, chop celery, orange bell peppers and onion. Sauté them, and add to boiling water. Season to taste, and allow them to cook until they're done.
Sliced Roma Tomatoes