Polar transport — where it appears
A pump that works uphill
The mechanism that actually has molecular support behind it does not use a diffusing inhibitor at all. Cells move auxin towards whichever neighbour already has more of it, which is the opposite of what transport is supposed to do — and it produces a spacing from a field that started uniform to within six per cent.
A growing organ is part of the rule
Every model on this site places primordia on a surface and then treats the surface as furniture. But the surface grows between one placement and the next, and that growth reaches the rule through the only channel it has — where the neighbours are. What looks like a boundary condition turns out to be a term in the model.
Named alongside it
The objects these essays reach for when they reach for this one.
AuxinMechanismBasinDescription versus mechanismElongationEpitheliumHonest limitsMeristem growthModel scopeNoisePeak selectionThe placement rule