In computer graphics, procedural methods and Lsystems are common approaches to model complex botanical trees. In contrast to previous tree modeling systems, we propose linking rules, parameters and geometry to semantic entities. This has the avantage that when an entity is clicked in the viewport, its parameters can be displayed immediately, and viewport editing operations can be reflected in the parameter set. Furthermore, we store the entities in a hierarchical data structure and allow the user to activate recursive traversal via selection options for all editing operations. Therefore, viewport or parameter changes can be applied to a single entity or many entities at once, and only the geometry for the affected entities needs to be updated. The proposed user interface aims at simplifying the modeling process.