Rattlesnake pole beans are an heirloom bean varieties the grows up walls, stakes, nets, and trellises that are an easy-to-grow type of climbing (or "pole") bean. The entire beans can be eaten as you would string beans or they can be grown to maturity, shelled, and then eaten as beans. Rattlesnake beans are green but they become camoflauge-like with purple on green as they mature.