Studies on the Role of the Leaf Epiderm in Photoperiodic Perception in Kalanchoe Blossfeldiana

Experimental blocking of the stomatal apertures of single induced leaves by vaselining, or entire removal of either lower or upper epiderm by stripping, indicate that the leaf epiderm must play a significant role in photoperiodic perception. The results do not, however, allow a clear decision to be made as to whether the function of the epiderm is exerted through stomatal control of the internal atmosphere of the leaf, or through some direct perception by the epidermal cells themselves.