Yams are a vegetable, like a sweet potato. On the Trobriand Islands, they are a staple, a currency, and the substance of several rituals. They are stored in so-called yam houses. These are often richly decorated and placed in the middle of the village for everyone to see. 

The villagers plant yams in their gardens. They are harvested in the fall. The village chief is the only one who has the right to take yams out of the yam house, but he is also responsible for the welfare of the villagers and obliged to look after them.