Transport – water, minerals, sugars. Support – hold flowers and leaves up toward the sun.
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Transcript of Transport – water, minerals, sugars. Support – hold flowers and leaves up toward the sun.
Transport – water, minerals, sugars
Four functions of stems
Support – hold flowers and leaves up toward the sun
Four functions of stems
Storage – of extra food, and sometimes water (onion, garlic, sugar cane, cacti)
Four functions of stems
Food making – carry out photosynthesis – only can occur if stem is green (cactus, bamboo, garden veggies)
Four functions of stems
Meristem – area (usually at the tip of the stem) where growth occurs
Stem parts:EXCEPTION!!
Stem parts
•Node – the area where a leaf is attached to a branch•Internode – the area between nodes
Cortex – storage tissue (same as the root) Vascular bundle – same as a vascular
cylinder. Contains xylem, phloem and cambium
Stem Parts
Bark – tough, protective tissue on the outside of woody trees
Pith - dead wood in the center of the tree
Stem parts
Herbaceous – extremely dependent on water (turgor pressure)◦ Characteristic of monocots
Woody stems - ex – trees, vines, hedges, bushes◦ Characteristic of dicots
Two basic types of stems:
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
Monocots vs Dicots:
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.
Annual rings
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.
Types of wood
Two major types of sweetener come from the stem of the plant – table and brown sugar (from sugar cane) and maple syrup
Sweeteners
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
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
Specialized types of stems
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
Misc.