1. Taproot- one main root that grows straight down. Enterprise: Plant Science Unit: Basics of Plant Science Factor: Information Needed I. Struct-ures Root systems 1. Taproot- one main root that grows straight down. a. used for food (carrots,etc) b. drought tolerant 2. Fibrous root- many small roots. a. tie up soil (many grasses) b. not as drought tolerant 3. Adventitious roots- specialized roots that develop .

B. Stems- there are many types. 1. Woody- tough and winter hardy 2. Herbaceous- green and die back. 3. Modified stems (specialized) a. bulbs- onions, Easter lilies b. corms- thickened stems c. rhizomes- horizontal underground stem d. tuber- potato e. stolon- (runner) above ground horizontal stem (strawberry) C. External stem parts:

Stem Part ID Terminal Bud (false) Terminal Bud (true) Auxiliary bud Node & Internode Bud scales Bundle Scar (Small dots) Leaf scar Lenticels

D. Internal stem & root structures: 1. Xylem- carry water & minerals up. 2. Phloem- carry food and nutrients down. 3. Structures differ for subclasses: a. monocotyledon- xylem and phloem are in separate rings. (grasses) b. dicotyledon- xylem and phloem in vascular bundles. (broad leaved plants)

E. Leaves- manufacture food through photosynthesis 1. Leaf shapes, margins, tips, and bases are important for identification purposes. 2. Leaf arrangements are also important identifiers: a. Simple- alternate, opposite, whorled. b. Compound- palmate, pinnate, Bipinnate. 3. The simple leaf parts include:

Leaf parts Tips Sinus Incised Leaf parts Lobe Midrib Margin Petiole Base Raised gland Stipule

F. The flower is the sexual part of the plant. 1. The male part is the stamen. 2. The female part is the pistil. a. perfect flowers contain both male and female parts. b. an imperfect flower has only male or female parts, not both. 3. Flowers become fruits, nuts, or seeds.

II. Physi-ology Physiology is the study of function. 1. Understanding plant function will allow success in growing them. B. Photosynthesis: 1. Is the process in which light energy is converted into stored chemical energy (sugar). 2. Carbon dioxide + water in the presence of chlorophyll and light form sugar, oxygen, and water a. chlorophyll is the green pigment in plants

C. Respiration is the process of breaking down sugar into heat energy. 1. Sugar and oxygen are used by the plant to produce energy. Carbon dioxide and water are by-products. D. Transpiration is the process of losing water vapor through stoma 1. Plants wilt if too much water is transpired. E. Osmosis is used by the plant to bring in water and nutrients

Plants require certain chemicals and soil pH to grow successfully. III. Plant Nutrition Plants require certain chemicals and soil pH to grow successfully. B. There are 16 nutrients needed for plant growth. 1. “C. Hopkin’s café, mighty good.” stands for: carbon, hydrogen, oxygen, phosporus, potassium, nitrogen, sulfer, calcium, iron, and magnesium. The others are boron, copper, chlorine, manganese, molybdenum and zinc.

2. The three that are fertilized for the most often are Nitrogen (N), Phosphorus (P), and Potassium (K). a. A 15-24-50 fertilizer would have 15% N, 24% P, and 50%K. C. pH is the measure of acidity or alkalinity of the soil. 1. pH of 7 is neutral 2. Below 7 is acidic, lime is added to raise it towards 7. 3. Above 7 is alkaline, sulfur is added to lower it closer to 7. 4. Most plants like a pH of 6 to 7.

IV. Plant Repro Reproducing plants is often referred to as propagation. There are two basic types: Sexual propagation- seeds a. germination- Asexual propagation Asexual propagation methods include 1. Stem cuttings- uses pieces of the stem

2. Leaf cutting- works on many indoor houseplants 3. Root cuttings are used on older plants with large root systems in the dormant season 4. Layering- is the process of using a stem while it is still attached to the plant.

5. Division- is the process of cutting the main plant into several pieces 6. Grafting- a piece of one plant is attached to another plant. 7. Tissue culture- done with small pieces in a laboratory setting.