Alfalfa, called lucerne in Britain, South Africa and Australia, is a perennial of the pea family that usually lives four to eight years, with leaves in threes, clusters of mostly purple flowers and roots that can reach deep groundwater. It is thought to have arisen in south-central Asia and been first farmed in Central Asia; Pliny records that it reached Greece around 490 BC with the Persian invasion, and was called the Median grass. Spanish colonists carried it to the Americas in the sixteenth century to feed their horses, and today it is grown worldwide as forage, cut for hay and silage or grazed. The English name came through Spanish from an Arabic word, while lucerne was borrowed from French. Grieve describes a deep-rooting plant with spikes of violet-blue, clover-like flowers, prized for fattening horses and cattle and for raising the milk yield of cows. In magic Cunningham gives it to Venus and earth and to prosperity: a little jar of it is kept in the pantry or a cupboard so that the household never goes short of food or money, and it is added to money spells.