The plant family Solanaceae contains important foodstuffs such as the potato, tomato and aubergine, together with powerful poisons including mandrake, henbane and deadly nightshade. In the first article in this short series on the family, the history and importance of the potato are described. It was first cultivated by the Inca people in the altiplano of the Andes in prehistoric times. Then it was translocated to Europe by the Spanish invaders. Originally reviled as'peasant food', it was regarded with great suspicion as an evil plant and a potential cause of leprosy. Over several centuries it gradually became established throughout Britain, France and the continent, and in particular in Ireland, where its growth allowed the population to expand very rapidly between 1750 and 1850. In the late 1840s, nemesis arrived in the form of the potato blight and the Irish famine. The 'tatties' went black, a great hunger ensued and thousands died. Later, the causative fungus was isolated and steps were taken to avoid further similar disasters. It is not generally appreciated that potatoes can be poisonous if they are turning green or sprouting (chitting). The tuber is then producing toxic quantities of the alkaloid alpha-solanine. The clinical syndrome of potato poisoning is described briefly.