Introduction to Horticulture Plants Parts

A World Without Plants  Find a Partner  On your note card  Identify why plants are so important to the world  Provide Examples

Parts of a Plant  Leaves  Stems  Roots  Flowers  Fruits or Seeds

Leaves  The FOOD FACTORY  Produces all the food required by the plant or animals  Leaf Structure  Petiole – leaf stalk  Blade – flat, large part of leaf  Midrib – large center vein  Veins – structural framework  Margin – edge of leaves (assists in ID)

Leaves  Internally –  Epidermis – single layer of cells that is the skin of the leaf – protect leaf from excessive moisture loss  Guard Cells – open and close a small pore on the underside of the leaf (stoma)  Allows leaf to breath and transpire  Transpire – give off moisture and exchange gases (oxygen and carbon dioxide)

Leaves  Transpiration is the evaporation of water through plant leaves and stems through the stomata (necessary for survival)  Transpiration slows when adequate water is unavailable (plant will begin to wilt)  If wilting continues into the evening, the plant needs more water to prevent damage  Extreme Drought – stomata close and photosynthesis slows or stops

Leaves  Transpiration  Cools the Plant  Maintains the flow of nutrients and manufactured food from root to top

Photosynthesis Carbon Dioxide + Water + Light Energy = Glucose + Oxygen  672 Kilocalories of Light – (1 molecule of glucose and 6 molecules of oxygen)  Carbon Dioxide enters through the Stoma  Food made in the Leaves travels DOWN through the stem to the roots  Food is used by plant or stored in the stem or root in the form of sugar, starch, or protein

Respiration  Respire – 24 hours a day  Respiration – plant consumes oxygen and gives off carbon dioxide (just like us and animals)  Roots, Stems, and Leaves all use oxygen  As they grow they use oxygen and give off carbon dioxide  BUT – they produce more oxygen through photosynthesis than they consume

BIG DIFFERENCE Photosynthesis 1. Food Made 2. Sun’s Energy Used 3. Carbon Dioxide Used 4. Oxygen Given Off 5. Produces Sugar & Starch 6. Requires Light 7. Chlorophyll must be Present Respiration 1. Food Used 2. Energy Released 3. Carbon Dioxide Given Off 4. Oxygen Used 5. Produces Carbon Dioxide & H2O 6. Goes on All Day and Night 7. Carried on in All Cells

Stems  TWO Main Functions 1. Movement of Materials  Water and Minerals (Roots – Up) [Xylem]  Manufactured Food (Leaves – Down) [Phloem] 2. Support of the Leaves and Reproductive Structures  Flowers, and Fruits or Seeds (Reproductive Structures)

Stems  ECONOMIC IMPORTANCE  Potato (Modified Stem) – USED FOR FOOD  Asparagus – USED FOR FOOD  And Several Others  Trees – trunks – USED FOR BUILDING MATERIALS

Roots  Anchor and hold plant Upright  Absorb water and minerals from the soil  Store large quantities of plant food  Propagate or Reproduce some plants  (First Three are Essential to All Plants)

Roots  Contains  Xylem – Water and Minerals Up  Phloem – Manufactured Food Down  Root Hairs – absorb moisture and minerals  Important for Cash Crops  Carrots, Beets, Radishes, Sweet Potatoes  Fibrous vs. Tap  Monocot vs. Dicot  Fibrous are easier to transplant

Flower Fruit Seed  The Beauty of a Flower is necessary to Attract Insects  When visited:  Fertilize by pollination (Beginning of Fruit & Seed)  Fruits and Seeds are Attractive so:  Birds and Animals will eat, collect, and spread them

Flower  Complete  Male and Female Parts – Can pollinate themselves  Contain: Sepals, Petals, Stamens, and Pistil  Incomplete  Male – OR – Female Parts  Contain: Sepals, Petals, Stamens (Male) Pistil (Female)

Exit Slip  With Partner  Back of Note Card  3 Things you Now Know, that you Didn’t Know when you walked in.