Length, Width, and Pattern of Regenerative Vessels along Strips of Vascular Tissue

The effect of stem girdling on vessel differentiation was studied in Acer rubrum by cinematographic analysis and by vessel-length distribution measurements. Partial girdling, presumably an obstruction to the flow of auxin, increased the rate of vessel differentiation in the bottleneck area, resulting in numerous small regenerative vessels. The regenerative vessels that were formed along an intact, longitudinal strip of cambium were short and narrow, presumably because of the local high auxin concentration. Numerous short and narrow vessels are a safer water-conducting system than wide and long vessels.