Researchers studying the patterns that veins form in leaves have found
that a simple mechanical model may be at work in all leaves, regardless
of plant variety. Leaf vein networks resemble webs of ropes and threads.
At points where a small vein joins a large vein, the angles between
the smaller vein and the larger ones approach 90 degrees, much like
the angles formed by pulling on a light thread tied to a taut rope (green
arrow). At a three-way junction of similarly sized veins, the angles
between the veins are all roughly 120 degrees (red arrow). The resemblance
to rope webs may seem superficial, but the model could lead to a deeper
understanding of the universal principles that guide leaf formation
Reported by: S.
Bohn, B. Andreotti, S. Douady, J. Munzinger, and Y. Couder, Physical
Review E, June 2002.
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