1. Special Defenses
BASEic Botany

2. Plant Evolution
Over time plants have evolved with animals. The development of special defense structures allow plants to survive!

3. How plants ‘fight’ Can plants fight?
How do they keep herbivores and insects from eating them?

4. Plant Defenses Physical defenses Chemical defenses Thorns Spines
Resins
Odors
Toxins

5. Every plant is unique!

6. Thorns
Modified stems or branch
Can be simple or branched

7. Gymnosperm buxifolia - Thorns

8. Citrus Thorn

9. Spines Modified leaves
Not only do they aid in defense they can help shade the plant from harsh environments

10. Fouquieria splendens - Spines

11. Spine Example
Iacacia xanthophloea

12. Review: Thorns are modified ______________
Spines are modified ______________

13. Thorn or Spine?

14. Thorn or Spine?
Answer: Thorn

15. Thorn or Spine?

16. Thorn or Spine?
Answer: Spines

17. Thorn or Spine?

18. Thorn or Spine?
Answer: Thorn

19. Your Task is to sort through a bag of common plants that are found locally and determine if they utilize thorns or spines. Be careful handling the plants!