Expression of form and pattern in plants - A role for biophysical fields

Coordinated or 'field' behaviour of cells of a tissue can be treated as an interaction between signals and a responding system. When the response involves the reaction of similar cells to a gradient, the field properties are thought to reside mainly in the signal. It is not generally recognized that initially uniform properties in the responding tissue can contribute to the specification of geometrical detail. One such feature is that a tissue may have an intrinsic wavelength, e.g. for the diameter of a new-forming organ. Another is tensor properties. Both features can greatly expand the role of signals in the expression of pattern.