1. Understanding Stem Anatomy

2. Describe the functions of a stem.
Recognize the external structures of a stem.
Analyze the internal structures of a stem.
Distinguish between the different types of specialized stems.

3. What are the functions of a stem?
Responsible for the size and shape of a plant
Made of different materials
Wood
Herbaceous or soft

4. What are the functions of a stem?
Support the leaves
Move water, minerals, and food throughout the plant
Translocation
Help produce food through photosynthesis
Store food that has been manufactured

5. What are some of the structures on the outside of a stem?
Terminal bud
Growing point at the tip of the stem
Lateral bud
Side bud on the stem
Node
Where the leaf is attached to the stem
Internode
The area between leaves
Leaf scar
Scar where leaf falls off of the stem
Bud scale scar
Scar left behind from last year’s growth
Lenticels
small spots on the stem that allow exchange gases with its environment

6. What are some of the structures on the outside of a stem?

7. What are some of the structures inside a stem?
Two ways interior stem tissue is organized
Scattered bundles
found in monocots.
Rings
found in dicots.

8. What are some of the structures inside a stem?
Three important internal tissues
Xylem
Transports the water and minerals throughout the plant
Found closer to the center of the stem
Phloem
Transports food that is produced in the leaf to the rest of the plant
Found toward the outside of the stem
Cambium
Responsible for the production of new xylem and phloem
Causes growth in girth of the stem
Found between the xylem and the phloem

9. How can we use the internal structure of a tree stem?
Heartwood
Darker wood to the center of the tree
Provide strength and no longer function in conducting materials
Sapwood
Lighter wood circling the
heartwood
Actively conducts water
and dissolved minerals

10. How can we use the internal structure of a tree stem?
The age of a tree can be determined by counting annual growth rings.
Rapid growth (spring and early summer) = large cells with thin walls = large in diameter
Slow growth (mid-to-late summer) = smaller cells and have thicker walls

11. What are some different kinds of specialized stems?
Bulb
Very short flattened stem that has several fleshy leaves attached to it
found beneath the soil
Example = onion
Corm
A spherical structure
Entire structure is stem
Example = gladiolus

12. What are some different kinds of specialized stems?
Rhizome
A thick underground stem that lies horizontally
Example = Hostas and Mother-in-law’s Tongue
Tuber
A swollen tip that stores food
Example = Irish potatoes
Stolon
A horizontal stem that lies above the ground that are involved in the spreading of the plant
Example = Strawberries

13. What are some different kinds of specialized stems?