Résumé
Apical meristems are small embryogenic regions, located at the tip of plant axes, that build up plant organs by cellular division. The production of the meristems depends on their internal physical, physiological and genetic state and is controled by contextual factors (like micro-environment, availability of nutrients, etc.). In principle, the number of variables that may be used to define the state of a meristem, taking account the nature and the concentrations of molecules in each cell, their position, the physical stresses at each point, the geometry of cells, their genetic contents, etc., is infinitely large. Due to this intrinsic complexity, and to the current lack of hindsight on processes at such small scales, the connection between a meristem state, its micro-environment and what it produces at varying time scales seems until now largely out of reach.