Nodulation of rooted leaves in leguminous plants

Summary Root formation was obtained on the petioles of detached leaves of several leguminous plants, particularly on the primary leaves of bean. Root formation is easily obtained in artificial light at a temperature of 22 to 24°C. In the greenhouse it is optimal in early spring and late autumn. During hot summer seasons no roots but callus was formed on the petioles. Root formation was inhibited when the pulvinus was left on the petiole. Nodulation of the rooted leaves is inhibited by combined nitrogen and high temperatures. The optimum light intensity for rooted leaves is low in comparison with that of intact plants. Far-red light reduces root-nodule formation; its inhibitory effect is partly eliminated by subsequent irradiation with red light.