Potatoes are tubers, or swollen underground stems that form as a storage location for starch.
Potatoes are grown from cut pieces of tubers grown in northern areas the previous season, usually referred to as seed potatoes. Common red-skinned varieties include Red Norland, La Rouge, La Soda, Viking, and Reddale. White-skinned varieties include Superior, Norchip, Crystal, Kennebec, and Irish Cobbler. Russet-skinned varieties include Norgold and Norkotah. Varieties differ in texture as well.