Abstract

A geometrical model is proposed that describes the emergence of a primordium at the shoot apex in Dicotyledons. It is based on recent fundamental results on plant morphogenesis, viz.: – the emergence is preceded by the reorganization of the microtubules of the cortical cytoskeleton, leading to a new orientation of the synthesis of the cell wall microfibrils; – the resulting global stress is related to the general orientation of the cell growth.