1. Roots Just as important as stems and leaves…. Major Functions:
1. Serve as an anchor
2. Conduct nutrients and water
3. Store food
(ex. sweet potatoes, carrots, radish, turnip, beet)

2. Root Functions

3. Root Development Primary root develops from the embryo
1. If primary root becomes the main root=Taproot System

4. Root Development
2. If primary root stops growing early on and new roots grow from the stem, it is a Fibrous Root System

7. Fibrous vs. Taproot

8. Root Hairs Grow from epidermal cells of roots
Only occur in first ¼ of root tip
Only live about 10 days
Absorb water and nutrients from soil particles

9. Function of Root Hairs

10. Root Hairs

11. Specialized Roots

12. Food Storage Roots Most roots store some food
Some are enlarged to store starch and other carbohydrates
Examples: sweet potato, carrot, beet, radish

13. Water Storing Roots Produced by plants in arid regions
Can be quite large (159 lbs.!)
Examples: Manroot

14. Manroot
Grows close to ground: perennial vine Roots can be several meters long and over 100lbs.

15. Pneumatophores
Extend above the surface of water for plants that grow in swampy areas
Helps roots exchange gases
Example: Mangrove

16. Mangrove

17. Aerial Roots Roots that occur above the surface of the soil
Examples: prop roots in corn (support in high wind)

18. Aerial Roots Continued
Adventitious roots in ivy for climbing

19. Poison Ivy

20. Contractile Roots Help to pull the plant deeper into the soil
Occurs from year to year
Examples: Lily, Dandelion

22. Parasitic Roots Peg-like projections penetrate host’s stem
Usually in plants that do not contain chlorophyll (can’t make food)
Examples: pinedrops, dodder
(one organisms benefits, one is harmed)

23. Pinedrops

24. Dodder: NO Chlorophyll
—Not green!

25. Buttress Roots Huge roots near base of trunk
Usually in trees that grow in shallow soil
Rainforest environments
Example: many tropical trees

26. Buttress Roots

27. Buttress Roots

28. Dicot Root Tip

29. Cross Section of Root

30. Modified Stems/Roots