Previous Steps

• 1b – Alternate leaf arrangement on stem — go to 18
  • 18a – Leaf simple — go to 19
    • 19b – Thornless — go to 22
      • 22d – All leaves lobed — go to 23
        • 23a – Pinnate ventation — go to 24
          • 24a – Leaves clustered towards stem tip. Pith is 5-angled or star-shaped — go to 25
            • 25a – Tips of lobes are pointed or bristle-tipped — go to 26

Current Step

• 26a – Sinuses of lobes are indented more than halfway to center vein — Pin Oak

• 26b – Sinuses of lobes are indented less than halfway to center vein — Red Oak

Resources

• Identifying Broadleaf Flowering Trees and Shrubs, CMG GardenNotes #173
• List of trees in this key
• Glossary of Terms
• Front Range Tree Recommendation List
• Online CSU Extension publications on Tree and Shrub Selection