Phyllo

137.5°. one number, every sunflower.

pack seeds by one angle — perfection lives at 137.5° exactly

One divergence angle, 137.5 degrees, packs seeds with no gaps and no spokes, because it comes from the golden ratio, the number no simple fraction approximates. Sunflowers and pinecones converge on it exactly.

Concepts: phyllotaxis, symmetry.

An interactive you play with one thumb, on Wundr.