Beets, potatoes, carrots, celeriac, parsnips, turnips, jicama, and yams are all roots, and all contain starch. Seeds also contain starch, which provides the necessary energy to help them grow into a plant. Rice, oatmeal, corn, wheat, barley, beans, peas, lentils, soybeans, and chickpeas are all seeds, and all of them contain starch, too.
