2. rye

3. A young root –the first organ to emerge during seed germination---WHY?

5. Adventitious roots

6. Root tip
Slimy layer
root hairs
rootcap
Root apical meristem

9. epidermis
cortex
Cross section of primary root
endodermis
Vascular cylinder
stele

11. epidermis
cortex
Cross section of primary root
endodermis
Vascular cylinder
stele

12. pericycle
Primary xylem
Primary phloem
xylem
Cross section of primary root

13. Dicot root cross section
Stele:
A = xylem
B = phloem
C = endodermis
D = pericycle
Dicot root cross section

14. Zea sp. root cross section

16. storage

17. Pneumatophores -- for breathing in waterlogged soil

18. Contractile roots --thickened specialized roots at the base of a corm, bulb, or other organ which is designed to shrink vertically under conditions of seasonal drought  that helps position this plant part at an appropriate level in the ground.

19. Haustoria – suckers of parasitic plants for obtaining nutrients from their hosts

20. Mycorrhizae –mutualistic relationship between plant roots and fungi
Pinus strobus with
Amanita muscaria

21. Root nodules --–mutualistic relationship between plant roots and N-fixing bacteria