By Harold McGee
The use of the common bean in Peru was predated by the larger lima bean—the name derives from Peru’s capital—which was native to Central America and domesticated somewhat later than the common bean. Both species were exported to Europe by Spanish explorers. The lima bean was introduced to Africa via the slave trade, and is now the main legume of that continent’s tropics. The wild type and some tropical varieties contain potentially toxic quantities of a cyanide defense system, and must be thoroughly cooked to be safe (common commercial varieties are cyanide-free). Lima beans are eaten both fresh and dried.