Romanesco broccoli (aka Romanesco cauliflower) is a quite strange (albeit tasty) vegetable that looks otherwordly in its freaky fractal formations. Every bud is self-similar, resulting in a logarithmic spiral. Now, researchers at the French National Centre for Scientific Research have determined that the natural (approximate) fractal nature occurs because each bud is a failed flower that becomes a shoot that produces a new flower that fails and so on. By analyzing the genes and developing a 3D computer model, François Parcy and colleagues teased apart the biological mechanism behind the beautiful shapes. From New Scientist:
"They start as flowers then lose their identity," says Parcy. "If you imagine a firework, it explodes and makes light. It's like if each of them was exploding again and again. And what you get, the structure of this cauliflower, is the result of all those consecutive explosions."
The difference between regular cauliflowers and Romanesco is that each individual failed flower is visible in the final Romanesco. This is because Romanesco shoots produce more buds at an accelerating rate which lifts the growing tip away from the centre of the growing cauliflower, creating the familiar array of conical shapes that characterise the Romanesco.