Is it possible to assign a custom block to one of the plant species representation types?

Yes it is.

  1. 1. Create the geometry to use as one of the representation types for the plant species.
  2. 2. Save it as a new file in your PC. (Make sure this geometry has its bottom center point located on the document origin coordinates). You can use the “File > Export with Origin..” option to save the model as a new file and set its base point.
  3. 3. Select the plant species to edit, from the Selection list, in the top left side of the Lands Edit Panel. (Make sure no object is selected to display the list of plant species inserted in the model).
  4. 4. In the Properties area of the Lands Edit Panel, under the Species tab, select the Change button of any representation type to open the block explorer and look for the file you have created before.