Why Plants Follow Fibonacci

Plants grow by adding one leaf, seed, or petal at a time, and each new one needs sunlight. If leaves stacked straight up, lower ones would sit in the shadow of upper ones. So plants rotate each new leaf by a fixed angle — and the angle that maximizes sunlight for every leaf is 137.5°, the golden angle.

Multiply this angle across many leaves and the positions trace out Fibonacci spirals. A sunflower with 34 spirals one way and 55 the other is solving a packing problem with the golden ratio. Pineapples and pine cones commonly show 8 and 13. The counts are usually consecutive Fibonacci numbers, because most other angles leave gaps or overlaps — though not every plant complies. The largest sunflower survey found roughly a quarter of heads departing from the standard pattern, some following related sequences like the Lucas numbers (47 and 76).