Producing patterns in plants.

The article provides a quantitative analysis of the process of capitulum growth and the gradual but controlled process by which elements within the capitulum become destined to form individual flowers. The data provide a foundation for the modelling of flower formation and for linking the observed parameters of floral morphogenesis with the wealth of molecular data on organogenesis in plants. An analysis of auxin flux and distribution during leaf initiation is also presented. The situation in the capitulum may be linked with the spatial and temporal control of factors specific to flower formation.