Macroscopic view of the healing process in girdled stems. A: Increase of stem diameter above the wound 10 days after girdling. B: First growth of parenchymatous tissue causes a bulge in the upper edge of the wound (40 days after girdling). C: Lumpy appearance 60 days after girdling, caused by the development of numerous protuberances in the upper edge. D: Column-like structures developed from the protuberances in the upper edge and axial parenchyma (see text for details) (100 days after girdling). E: Column-like structures reaching the lower margin and restoring the vascular connection (150 days after girdling).