Abstract: In the traditional L-system，the production of branch structure is different from the growth of stems while shaping the characters of plants.The grammar system about structure of plants is created by an iterative procedure，and visualized using turtle interpretation.The method is difficult in manifesting the life of plants.A generalized L-system model is proposed in this paper.In this model，substructure is the unit of growth with physiological age and chronological age，and the dynamic growth is proceeded by the hidden Markov procedure，and then the developed plants have the stochastic quality in accordance with botanical principles.A given instance shows the proposed model is quick and effective in modeling plants.

Key words: growth of virtual plants, generalized L-system, substructure, hidden Markov model, adjoint function

摘要： 传统的L系统对于植物生长特征的表达是将表示分枝结构和枝节生长的产生式加以区别，迭代生成描述植物结构的文法系统并结合海龟解释实现植物的可视化模拟，很难真正体现植物生长过程中的“生命”特征。综合考虑L系统对植物生长的表达能力，将具有一定生理年龄和生长年龄的生长单元视为子结构，考虑植物生长的随机特性，植物的动态生长按照隐式马尔可夫过程进行状态转移，从而提出一种广义的L-系统模型，符合植物本身的生长机理。实例验证表明，提出的模型可快速、有效地实现虚拟植物的可视化模型的建立。

关键词: 虚拟植物生长, 广义L-系统模型, 子结构, 隐式马尔可夫模型, 伴随函数