Abstract: Creating 3D plant models is often a hard and laborious task. To make it easier and more natural, we propose a sketch-based interface for modeling single-compound plant structures with phyllotactic arrangements. Our approach is based on the traditional illustration technique of concept sketching. The user sketches the key construction lines for the main plant body and lateral organs. Our system then automatically constructs the 3D plant arrangement in phyllotactic patterns rendered as pen-and-ink line drawings. The user is then able to edit the model by oversketching the construction lines, adjusting density of lateral organs, and specifying different phyllotactic patterns. We demonstrate the capabilities of our system for a variety of plant models.