These branching weeds were generated as applications of L-systems, starting with the axiom, using the string replacement rules listed next to each corresponding figure, and making turns according to the angle specified. All symbols are replaced simultaneously; those without replacement rules are retained unaltered. The symbols are interpreted as in "Turtle Graphics":
| Symbol | Interpretation |
|---|---|
| B F G X | move and draw line |
| + | turn to the left |
| - | turn to the right |
| [ | begin side branch |
| ] | end side branch |
| Twisted twig | Scaled twig | Needled twig | Grass seed | Woody weed | Standing bush | Leaning bush |