Previous Steps
- 1a – Opposite leaf arrangement on stem — go to 2
- 2a – Leaf simple — go to 3
- 3b – Leaves are unlobed — go to 11
- 11b – Leaf margins finely serrated — go to 12
- 3b – Leaves are unlobed — go to 11
- 2a – Leaf simple — go to 3
Current Step
- 12a – Sharp thorn at end of stem. Some leaves may be sub-opposite and/or alternate — Common Buckthorn
