This research was initiated with a survey of the most significant alfalfa types of Tierra de Campos areas, collecting 56 seed samples. These samples were later analysed in the laboratory (seed), in the greenhouse (seedlings) and in field trials (plant) under irrigated and rainfed conditions for three years. At the same time, several varieties of different dormancy rates were used as controls. Discriminant functions were calculated for the groups identified by the cluster analysis with the objective of determining the best traits for the identification of the ecotype. Persistence, spring regrowth and rate of growth were the best.