BOTH CELL LINEAGES AND CELL-INTERACTIONS CONTRIBUTE TO STOMATAL PATTERNING

Mathematical models have been used as evidence concerning the mechanis ms of stomatal patterning. The details of epidermal development, howev er, provide direct evidence that has been often ignored. Lineages acco unt for at least part of the distance between neighboring stomata. Int eractions are also indicated by developmental observations, which show that interactions modify stomatal development rather than inhibit sto matal initiation. Models are useful when constrained by the available facts and when they indicate new concepts that account for unexplained phenomena. An example of such phenomena is the remarkable variability of the processes of epidermal development.