Advanced Meshing > Add Tree displays the following dialog.
It allows you to add a tree to a mesh region. You must first select beams as the branches of the tree. Please note that disconnected branches are not allowed. You have the option to deactivate the selected beams after the tree is created. This ensures that the selected beams will not be part of the structural model. Later, you can select all inactive members by Create > Select by Properties > Select Inactive Elements and then delete them if necessary.