diff --git a/src/build_models/auxingrowthplugin.cpp b/src/build_models/auxingrowthplugin.cpp
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--- /dev/null
+++ b/src/build_models/auxingrowthplugin.cpp
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+/*
+ *
+ *  This file is part of the Virtual Leaf.
+ *
+ *  The Virtual Leaf is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The Virtual Leaf is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with the Virtual Leaf.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *  Copyright 2010 Roeland Merks.
+ *
+ */
+
+#include <QObject>
+#include <QtGui>
+#include "../simplugin.h"
+
+#include "parameter.h"
+
+#include "wallbase.h"
+#include "cellbase.h"
+#include "auxingrowthplugin.h"
+
+#include "far_mem_5.h"
+
+static const std::string _module_id("$Id$");
+
+bool batch = false;
+
+
+// To be executed after cell division
+void AuxinGrowthPlugin::OnDivide(ParentInfo &parent_info, CellBase &daughter1, CellBase &daughter2) {
+	// Auxin distributes between parent and daughter according to area
+	double area1 = daughter1.Area(), area2 = daughter2.Area();
+	double tot_area = area1 + area2;
+	
+	daughter1.SetChemical(0,daughter1.Chemical(0)*(area1/tot_area));
+	daughter2.SetChemical(0,daughter2.Chemical(0)*(area2/tot_area));
+	
+	// After divisions, parent and daughter cells get a standard stock of PINs.
+	daughter1.SetChemical(1, par->initval[1]);
+	daughter2.SetChemical(1, par->initval[1]);
+	
+	
+	// Reset transporter values of parent and daughter
+	QList<WallBase *> walls;
+	foreach(WallBase *w, walls) { 
+		w->setTransporter(&daughter1, 1, 0.);
+	}
+	
+	//daughter1.LoopWalls(Wall::setTransporter(&daughter1, 1, 0.));
+	
+	
+	/* for (list<Wall *>::const_iterator w=daughter2.walls.begin();
+		 w!=daughter2.walls.end();
+		 w++) {
+		// reset transporter value
+		(*w)->setTransporter(&daughter2, 1, 0.);
+	}
+	*/
+}
+
+void AuxinGrowthPlugin::SetCellColor(CellBase &c, QColor &color) { 
+
+	// Red: PIN1
+	// Green: Auxin
+	if (c.CellType()==1) color = QColor("Blue"); 
+	else color.setRgb(c.Chemical(1)/(1+c.Chemical(1)) * 255.,(c.Chemical(0)/(1+c.Chemical(0)) * 255.),/* (chem[2]/(1+chem[2]) *255.) */ 0);
+	
+}
+
+
+
+void AuxinGrowthPlugin::CellHouseKeeping(CellBase &c) {
+
+	if (c.Boundary()==CellBase::None) {
+		if (c.Area() > par->rel_cell_div_threshold * c.BaseArea() ) {
+			c.SetChemical(0,0);
+			c.Divide();
+        }		
+		if (c.Chemical(0)>0.6) {
+			c.SetCellType(1);
+		} 
+		// expand according to auxin concentration
+   		c.EnlargeTargetArea(par->auxin_dependent_growth?(c.Chemical(0)/(1.+c.Chemical(0)))*par->cell_expansion_rate:par->cell_expansion_rate);
+	}  
+	
+
+}
+
+void AuxinGrowthPlugin::CelltoCellTransport(Wall *w, double *dchem_c1, double *dchem_c2) {
+
+	// leaf edge is const source of auxin
+    // (Neumann boundary condition: we specify the influx)
+    if (w->C2()->BoundaryPolP()) {
+		if (w->AuxinSource()) {
+			double aux_flux = par->leaf_tip_source * w->Length();
+			dchem_c1[0]+= aux_flux;
+			// dchem_c2 is undefined..!
+			return;
+		} else {
+			return;
+		}
+	}
+	
+	
+	if (w->C1()->BoundaryPolP()) {
+		
+		if (w->AuxinSource()) {
+			double aux_flux = par->leaf_tip_source * w->Length();
+			dchem_c2[0] += aux_flux;
+			// dchem_c1 is undefined...!
+			return;
+		} else {
+			
+			if (w->AuxinSink()) {
+				
+				// efflux into Shoot Apical meristem
+				// we assume all PINs are directed towards shoot apical meristem
+				dchem_c2[0] -= par->sam_efflux * w->C2()->Chemical(0) / (par->ka + w->C2()->Chemical(0));
+				
+				return;
+			} else 
+				return;
+		}
+    }
+	
+    
+	// Passive fluxes (Fick's law)
+    // only auxin flux now
+    // flux depends on edge length and concentration difference
+    int c=0;
+    double phi = w->Length() * ( par->D[c] ) * ( w->C2()->Chemical(c) - w->C1()->Chemical(c) );
+    dchem_c1[c] += phi; 
+    dchem_c2[c] -= phi;
+	
+    // Active fluxes (PIN1 mediated transport)
+	
+    // (Transporters measured in moles, here)
+    // efflux from cell 1 to cell 2
+    double trans12 = ( par->transport * w->Transporters1(1) * w->C1()->Chemical(0) / (par->ka + w->C1()->Chemical(0)) );
+	
+    // efflux from cell 2 to cell 1
+    double trans21 = ( par->transport * w->Transporters2(1) * w->C2()->Chemical(0) / (par->ka + w->C2()->Chemical(0)) );
+    
+    dchem_c1[0] += trans21 - trans12;
+    dchem_c2[0] += trans12 - trans21;
+	
+}
+
+void AuxinGrowthPlugin::WallDynamics(Wall *w, double *dw1, double *dw2) {
+
+	
+	
+    // Cells polarize available PIN1 to Shoot Apical Meristem
+    if (w->C2()->BoundaryPolP()) {
+		if (w->AuxinSink()) {
+			
+			dw1[0] = 0.; dw2[0] = 0.;
+			//dw1[2] = 0.; dw2[2] = 0.;
+            
+			// assume high auxin concentration in SAM, to convince PIN1 to polarize to it
+			// exocytosis regulated0
+			double nb_auxin = par->sam_auxin;
+			double receptor_level = nb_auxin * par->r / (par->kr + nb_auxin);
+			
+			dw1[1] = par->k1 * w->C1()->Chemical(1) * receptor_level /( par->km + w->C1()->Chemical(1) ) - par->k2 * w->Transporters1(1);
+			
+			dw2[1] = 0.;
+			return;
+			
+		} else {
+			dw1[0]=dw2[0]=dw1[1]=dw2[1];//=dw1[2]=dw2[2];
+			return;
+		}
+    }
+    
+    if (w->C1()->BoundaryPolP()) {
+		if (w->AuxinSink())  {
+			
+			dw1[0] = 0.; dw2[0] = 0.;
+			//dw1[2] = 0.; dw2[2] = 0.;
+			
+			// assume high auxin concentration in SAM, to convince PIN1 to polarize to it
+			// exocytosis regulated
+			double nb_auxin = par->sam_auxin;
+			double receptor_level = nb_auxin * par->r / (par->kr + nb_auxin);
+			dw2[1] = par->k1 * w->C2()->Chemical(1) * receptor_level /( par->km + w->C2()->Chemical(1) ) - par->k2 * w->Transporters2(1);
+			
+			dw1[1] = 0.;
+			return;
+			
+		}  else {
+			dw1[0]=dw2[0]=dw1[1]=dw2[1];//=dw1[2]=dw2[2];
+			return;
+		}
+    }
+    
+    
+    
+    // PIN1 localization at wall 1
+    // Note: chemical 0 is Auxin (intracellular storage only)
+    // Chemical 1 is PIN1 (walls and intracellular storage)
+    //! \f$ \frac{d Pij/dt}{dt} = k_1 A_j \frac{P_i}{L_ij} - k_2 P_{ij} \f$
+    // Note that Pij is measured in term of concentration (mol/L)
+    // Pi in terms of quantity (mol)
+	
+    double dPijdt1=0., dPijdt2=0.;
+    
+    // normal cell
+    double  auxin2 = w->C2()->Chemical(0);
+    double receptor_level1 = auxin2 * par->r / (par->kr + auxin2);
+    
+    dPijdt1 = 
+	// exocytosis regulated
+    par->k1 * w->C1()->Chemical(1) * receptor_level1 / ( par->km + w->C1()->Chemical(1) ) - par->k2 * w->Transporters1(1);
+	
+    double  auxin1 = w->C1()->Chemical(0);
+    double receptor_level2 = auxin1 * par->r / (par->kr + auxin1);
+    
+    // normal cell
+    dPijdt2 = 
+	
+	// exocytosis regulated
+	par->k1 * w->C2()->Chemical(1) * receptor_level2 / ( par->km + w->C2()->Chemical(1) ) - par->k2 * w->Transporters2(1);
+    
+    /* PIN1 of neighboring vascular cell inhibits PIN1 endocytosis */
+    
+    dw1[0] = 0.; dw2[0] = 0.;
+    //dw1[2] = 0.; dw2[2] = 0.;
+    
+    dw1[1] = dPijdt1;
+    dw2[1] = dPijdt2;
+}
+
+double AuxinGrowthPlugin::complex_PijAj(CellBase &here, CellBase &nb, Wall &w) { 
+	
+	// gives the amount of complex "auxinreceptor-Pin1"  at the wall (at QSS) 
+	//return here.Chemical(1) * nb.Chemical(0) / ( par->km + here.Chemical(1));
+	
+	double nb_aux = (nb.BoundaryPolP() && w.AuxinSink()) ? par->sam_auxin : nb.Chemical(0);
+	double receptor_level = nb_aux * par->r / (par->kr + nb_aux);
+	
+	return here.Chemical(1) * receptor_level / ( par->km + here.Chemical(1));
+	
+}
+
+void AuxinGrowthPlugin::CellDynamics(CellBase *c, double *dchem) {
+	// Note: Pi and Pij measured in numbers of molecules, not concentrations		
+		double dPidt = 0.;
+		
+		double sum_Pij = c->SumTransporters( 1 );
+		
+		// exocytosis regulated:
+	
+	dPidt = -par->k1 * c->ReduceCellAndWalls<double>( far_3_arg_mem_fun( *this, &AuxinGrowthPlugin::complex_PijAj ) ) + par->k2 * sum_Pij;
+	/*for ( list<Wall *>::const_iterator w = c->walls.begin();
+		 w!=walls.end();
+		 w++) {
+		if ((*w)->C1() == c)
+			dPidt +=  complex_PijAj( (*w)->C1(), (*w)->C2(), *w );
+		else
+			dPidt +=  complex_PijAj( (*w)->C2(), (*w)->C1(), *w );
+	}*/
+	
+	// production of PIN depends on auxin concentration
+	dPidt +=  (c->AtBoundaryP()?par->pin_prod_in_epidermis:par->pin_prod) * c->Chemical(0) - c->Chemical(1) * par->pin_breakdown;
+	
+	// no PIN production in SAM
+	if (c->Boundary() == CellBase::SAM) {
+			dchem[1]=0.;
+		dchem[0]= - par->sam_auxin_breakdown * c->Chemical(0);
+	} else {
+		
+		dchem[1] = dPidt;
+		
+		
+		// source of auxin
+		dchem[0] = par->aux_cons - par->aux_breakdown * c->Chemical(0);
+		
+	}
+	
+	
+	
+}
+
+
+Q_EXPORT_PLUGIN2(auxingrowthplugin, AuxinGrowthPlugin)