High compression of plant geometry is an important aspect in fast realistic visualization of plants. Hierarchical structuring plant morphology is a key factor for real time plant rendering, especially when pedestrian views, including both close-ups and far views, are requested. We present here a new geometric simplification method, called Viewdependent Hierarchical Foliage Simplification (VHFS). It aims to construct efficient multi-resolution models, faithful to botanical knowledge for sparse organs of trees, such as leaves, flowers and fruits. Both preprocessing and view-dependent rendering processes are considered hereby. In the preprocessing phase, sparse organs are simplified hierarchically with respect to the topological structure of the plant, i.e. to the plant branching order hierarchy and the phyllotaxy (or anthotaxy) groups. In the rendering phase, the simplification degrees for organs in different locations in the crown are defined from the current viewpoint. The selection of...