Being able to create and render plants and trees is very important for many aspects of computer graphics and can be useful, among others, for botanists, cartographers and game developers. Creating a virtual world and populating it with vegetation can be an extremely time-consuming task, because of the high number of models needed and their complexity. Many algorithms have been developed for the creation of procedural content, such as cities or vegetation. GALSYS explores the combination of two known methods, Lindenmayer Systems and Genetic Algorithms, by looking at both concepts individually and how they can interact. The implementation approach is presented through pseudocode and description of applied rules and functions also showing results and possible optimizations.