The growth retardant (2-chloroethyl) trimethylammoniumchloride (CCC) was incorporated in a nutrient medium on which isolated buds and scales of Wedgwood iris were cultivated. CCC inhibited elongation of the older of the two leaf primordia that were left on the explant. In the process of leaf elongation a competitive interaction relationship with gibberellic acid could not be established, although both growth regulators act in opposite directions. CCC did not retard flower formation, which process is promoted by gibberellic acid. CCC promoted the production of gibberellin-like substances in excised scales.