Growth Model for the Blue-Green Alga Anabaena catenula
This is a model for the cell division of a blue-green alga (Anabaena catenula). Each cell splits into a small cell and a large cell, with the smaller cell in the direction of the arrow. Large and small cells take 5 and 6 time-steps to split, respectively. The rule corresponds formally to a context-free grammar.
Based on ideas presented in: Jacob, C. 1995. Modeling Growth with L-Systems & Mathematica. Mathematica in Education and Research 4, no. 3.