When Prussia was hit by famine in 1744, King Frederick the Great, a potato enthusiast, had to order the peasantry to eat the tubers. In England, 18th-century farmers denounced S. tuberosum as an advance scout for hated Roman Catholicism. “No Potatoes, No Popery!” was an election slogan in 1765. France was especially slow to adopt the spud. Into the fray stepped Antoine-Augustin Parmentier, the potato’s Johnny Appleseed.