How it works
Draw a trunk. At its tip, add two branches turned equally to the left and right. Multiply their lengths by a fixed ratio and repeat at each new tip. The angle controls the spread; the length ratio controls how far the canopy reaches.
Where it began
A binary fractal tree is a general recursive construction, not a single shape with one securely established inventor and date. A related milestone is Aristid Lindenmayer’s introduction of L-systems in 1968 to model biological development. The date shown here refers to that formalism, not the invention of every fractal tree.