Concentrations of α-tocopherol in foliage samples of the forages annual rye, winter rye, red fescue, Kentucky blue-grass and white clover were determined. Concentrations of α-tocopherol increased with age in all four of the grasses tested during the six-week experimental period to values of 70.9, 80.9, 94.0 and 146.7 μg g −1 dry wt in annual rye, winter rye, red fescue and Kentucky blue-grass, respectively. White clover, the only legume forage tested, did not increase α-tocopherol concentrations with age, remaining at about 20 μg g −1 dry wt for each time sample. These results support the hypothesis that concentrations of α-tocopherol may act as indicators of biological age, although exceptions to this concept are likely to exist.