Fibonacci Spirals & Phyllotaxis

The golden angle and why plants count in Fibonacci numbers

Parameters

φ = 1.6180339…
Golden angle = 360°/φ² ≈ 137.508°
Fibonacci sequence:
Why Fibonacci? With divergence angle exactly 360°/φ², seeds pack most efficiently — no sector of the disk goes to waste. Any rational angle creates visible "spokes".

Spiral counts are always consecutive Fibonacci numbers. Sunflowers show 34/55 or 55/89 spirals. Pinecones: 8/13. Pineapples: 8/13/21.

Drag the angle slider away from 137.5° to see efficiency collapse.