Count a sunflower's spirals and you'll almost always land on a Fibonacci number

Sunflower heads, pinecones and pineapples arrange their florets or scales in two sets of spirals winding in opposite directions, and the spiral count in each direction is almost always a pair of consecutive Fibonacci numbers, like 34 and 55. The pattern follows from each new floret growing at a fixed 'golden angle' of about 137.5 degrees from the last one, which mathematician Helmut Vogel showed in 1979 packs seeds with near-optimal efficiency and no gaps, whatever the head's final size.

— Helmut Vogel, A better way to construct the sunflower head — Mathematical Biosciences, 1979