Modeling the architecture of expanding Fraxinus pennsylvanica shoots using L-systems

This paper presents a mathematical model of Fraxinus pennsylvanica (green ash) shoots, which yields realistic computer graphics images of shoot geometry, and makes it possible to visualize shoot expansion using computer animation. The model is based on the mathematical formalism of Lindenmayer systems (L-systems). The paper emphasizes the process of model construction, with the aim of making the methodology applicable to other plant species. The central issue is the identification of field data necessary to build a comprehensive developmental model of plant architecture. Key words: Fraxinus pennsylvanica, plant architecture, shoot expansion, modeling, L-system, computer graphics.