=====Yams===== [[Image:Kiekie yams.jpg|thumb|250px|Tongan farmer showing off his prize yams]] In the southern United States, '''sweet potatoes''' are often referred to as '''yams''', but these two plants are distinct from one another. Yam tubers can grow up to 2.5 meters in length and weigh up to 70 kg (150 pounds). In other words, they can get ''big''! Yams are a primary agricultural commodity in West Africa and New Guinea. They are important to this day for survival in these regions. Yam tubers can be stored up to six months without refrigeration, which makes them a valuable resource for the yearly period of food scarcity at the beginning of the wet season. Yams of African species must be cooked to be safely eaten because various natural substances in raw yams can cause illness if consumed. <br style="clear:both">
