Leaf has teeth on the edge

Leaf-stem flat. Many large teeth on edge. -- Bigtoothed Aspen

All trees
- Tree having broad leaves.
  - leaves simple.
    - Leaves and branches alternately arranged.
      - No thorns on branches.
        
        Only one type of leaf on tree.
        
        Leaf unlobed.
        
        Leaf has teeth on th edge.

This key was developed by "bt" in June 1982. It was put into HTML format by Stephen Ostermiller in July 1997. Copies of the entire guide in zip format that may be taken to camp on a laptop are available to those who write.