The nutrient content of Festuca vivipara (L.) Sm. plantlets from a site in the English Lake District were compared with that of seeds of the closely related species, F. ovina L. The almost linear increase in dry weight of plantlets throughout the growing season was associated with an increase in their mineral nutrient content derived from the parent plant. Their amino acid and soluble carbohydrate content also increased markedly with size. The relatively high levels of free amino acids and soluble carbohydrates in viable plant-lets contrasts with the generally low levels of these compounds usually found in mature seed of grasses. Viable plantlets contained three to four times the nutrient content of F. ovina seeds resulting principally from the larger dry weight of the plantlets. The growth and survival of plantlets is discussed in relation to the success of vivipary as a method of reproduction in arctic-alpine environments.