关键词: 植物形态结构模拟, L-系统, 曲率函数, 弯曲枝条

Abstract: Simulating bending branches is an important part of plant simulation and L-system is one of the significant methods of it.But it requires plenty of productions if L-system is applied to simulate bending branches.In this paper，functional L-system is presented，through adding the bending symbols and curvature functions to the productions.When modeling shapes of plants using functional L-system，without changing the number of productions，various shapes of trees with the same topological structure will be produced through adjusting the curvature functions.Functional L-system is a very concise description in modeling bending branches of plants，and the length of the branches can be easily controlled in programming.

Key words: simulation of shapes of plants, L-systems, curvature functions, bending branches