Recursion reflects natural phenomenon like fractals.
Lyndenmayer, a biologist, proposed L-system, a grammatical system
to describe the processes of plant development which consists of an
initial value and a collection of production rules. In [12] introduced
turtle symbols and led to turtle actions in L-system. Similarly, in [3]
also designed the turtle metaphor-based L-system environment by using simple symbols of ‘f, ’
in JavaMAL microworld environment. ‘f’ is a symbol to move a turtle forward at a certain length
‘’ is a symbol to rotate a turtle at a certain angle, and ‘[ ]’ is a symbol to save a turtle’s position
and recall it. Figure 11 shows the tree growing rules and tree images in each growing step.