INTEREST in malonic acid has been largely directed towards its role as a competitive inhibitor of succinic dehydrogenase. Very little attention has been directed towards the occurrence of malonic acid in plant tissues or toward the metabolism of malonic acid per se. In 1952 Bentley1 showed malonate to be present in about eighteen species of leguminous plants. Malonic acid has also been reported in species from families other than the legume family1–3. That malonic acid could be metabolized was established more than thirty years ago when it was shown that malonate could serve as the sole carbon source for certain bacteria4. More recent work established that malonate was readily metabolized by enzyme preparations from fungi5,6, mammals7,8, and plants9,10. The present communication reports a wide range of higher plants which possess the ability to metabolize malonate.