When the potato was first introduced in Sweden in the 19th century (by Jonas Ahlströmer among others), many people tried to eat the fruits (the little green "tomatoes"). Of course, since the fruits are poisonous (containing atropine), it took a while for the potato to become established in the Swedish household. Once people figured out that the root lumps are the edible part, it soon became the country's most important staple food. Not so strange, considering it tastes better and yields more food/acre than turnips.
Of course, nobody in Sweden knows what an acre is. God bless the metric system.