1. Four functions of stems
Transport – water, minerals, sugars

2. Four functions of stems
Support – hold flowers and leaves up toward the sun

3. Four functions of stems
Storage – of extra food, and sometimes water (onion, garlic, sugar cane, cacti)

4. Four functions of stems
Food making – carry out photosynthesis – only can occur if stem is green (cactus, bamboo, garden veggies)

5. Stem parts:
EXCEPTION!!
Meristem – area (usually at the tip of the stem) where growth occurs

6. Stem parts Node – the area where a leaf is attached to a branch
Internode – the area between nodes

7. Stem Parts Cortex – storage tissue (same as the root)
Vascular bundle – same as a vascular cylinder. Contains xylem, phloem and cambium

8. Stem parts
Bark – tough, protective tissue on the outside of woody trees
Pith - dead wood in the center of the tree

9. Two basic types of stems:
Herbaceous – extremely dependent on water (turgor pressure)
Characteristic of monocots
Woody stems - ex – trees, vines, hedges, bushes
Characteristic of dicots

10. Monocots vs Dicots:
Monocots have their vascular bundles scattered throughout, while dicots have their vascular bundles in rings
Monocots tend to be herbaceous, while dicots are generally woody

11. Annual rings
The result of the growth of xylem tissues. Year after year the wood produced by the cambium forms new layers. Springwood grows early in the season with many large xylem vessels. Summerwood grows later and has fewer and smaller xylem vessels. The differences in the texture of spring and summerwood are what produce the ring.

12. Types of wood
Heartwood – hard, dark dead inactive wood in the center of a woody stem. Xylem and pith become plugged and ceases to function
Sapwood – live, active, functioning wood outside the heartwood.

13. Sweeteners
Two major types of sweetener come from the stem of the plant – table and brown sugar (from sugar cane) and maple syrup

14. Brazil
645,300,182
 India
348,187,900
 People's Republic of China
124,917,502
 Thailand
73,501,610
 Pakistan
63,920,000
 Mexico
51,106,900
 Colombia
38,500,000 F
 Australia
32,621,113
 Argentina
29,950,000
 Philippines
26,601,400

15. Specialized types of stems
Stems used for food – white potato, rhubarb, onion, garlic, and sugar cane
Rhizome – thick, fleshy creeping underground stems that grow just below the surface of the ground (Iris)
Tubers – underground stems that are swollen with stored food, usually as starch (white potato)
Bulbs – stem is at the center, food is stored in layers of short, thick leaves that wrap around and protect the stem (onion and garlic)
Corms – similar to bulbs – thin scalelike leaves

16. Misc. Another food stem is asparagus
White potatoes are an underground stem called a tuber
Potatoes are the 4th most important food crop in the world and the only non grain in the top 5
Potatoes have only been know outside of the America’s for the last 500 years
Potatoes were one of the most important food crops in Ireland until 1843.
The average family ate 40lb of potatoes a week