Laws of branching in plants, with shadow and survey notes
Rules for how branches bend and grow, a sun-and-pyramid color note, and a planimetric sketch with measures
The sheet gathers Leonardo's rules on the branching of plants: branches bend more where they are thinner, opposite branches leave the central one straight while alternate ones bend it, thickness does not change from branch to branch, branches curve toward the sky and their angles grow more obtuse as they thicken, and bark splits only in the older part of a tree. Set among these are a note that shadows are seen as companions of the lit part, a color observation on a sun-lit pyramid, a question on why a liquid leaps up, and a large planimetric drawing annotated with measures.
On this page
How branches bend, bifurcate and attach leaves
The side of the angle bends more where the branch is thinner. Every bifurcation recomposes the whole part of the branch below it; the bends of the main branch equal the number of branches that do not meet it opposite; and the attachment of a leaf always leaves a trace.
Branches curve skyward and their angles open with thickness
Every branch curves toward the sky, the angles are equal, and the angles become more obtuse in the branches that grow thicker.
Tree crowns, aging, and the splitting of bark
The tops of trees are the masters of the principal branches; the more a tree ages the fewer branches it puts out, and a branch grows straighter when it generates fewer branches around itself. The bark does not split in a young tree but splits in the older part. A companion note observes where shadows are seen beside the lit part.
Sun, pyramid, and the color green
A figure of the sun and a pyramid lying on its side is lettered n, b, a, with the note that a b is green and n b is also green.
Planimetric drawing with measures
A planimetric drawing is annotated with the measures 25 and 22, set among the branch studies.
Why does the liquid leap up
A short question in the right-hand column asks why the liquid leaps back up.