Tumors were formed on germinating seeds of a hybrid of Lilium speciosum "Album" x L. auratum. Ferulic acid and the glucose ester were isolated from both pericarp and seeds. Tumors were induced on excised embryos only when the embryos were grown on nutrient agar containing ferulic acid. Tumors may result from the limited amount of glycosylation and from detoxification of ferulic acid.