Which crop, introduced from the Americas, ultimately became staple food in many parts of Europe and helped reduce famine?

1. NCERT lists 'Columbian Exchange' crops. 2. Sometimes the new crops could make the difference between life and death — Ireland's poor peasantry became dependent on potatoes. 3. Potato came to Europe from the Americas after Columbus's voyages. _Source: NCERT Class 10 History India and the Contemporary World - II, Ch 3 "The Making of a Global World", §Conquest ¶2_