Phyllotaxis
the spirals are counted, not admired
Generator

l-system

X → F[+X]F[-X]+X and F → FF, walked by a turtle turning 22.5°. 130 segments, and not one of them knows anything about light, water or auxin.
An L-system after 4 rewrites of two rulesX → F[+X]F[-X]+X and F → FF, walked by a turtle turning 22.5°. 130 segments, and not one of them knows anything about light, water or auxin.491 symbols · 130 segmentsa description, not a mechanism

Drawn at its defaults, in branching and transport. It carries a slider over angle, so the claim in its caption strip is restated at every stop rather than at one. It takes no options at all, so every essay calling it gets this exact drawing.

Called by 1 essay

the blast radius of changing it

Branching and transport

L-systems describe, they do not explain

Two rewriting rules and a turtle produce something indistinguishable from a plant, and there is no plant in it — no light, no water, no auxin, no mechanics. That is worth demonstrating precisely because the output is so convincing.

All 105 generators