Botany and Taxonomy for the Master Gardener

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Botany and Taxonomyfor the Master Gardener

• Original concept and text by Bruce Ide, Palm
  Beach County.
• Additional text and pictures by Jim Moll,
  Hernando County and Mark Shelby Sarasota County
  Extension Service

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Botany vs. Plant Physiology vs. Horticulture

• Botany is the science of plants
• Plant physiology is the science of plant function
• Horticulture is the practice of the science of
  plants

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Characteristics of Plants

• Growth
• Energy Transformation
• Response
• Reproduction
• Organic Composition

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What Makes a Plant

• Leaves
• Roots
• Stems
• Flowers

• Fruit
• Seeds
• Cellulose Cell Walls

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A Plant is a Living Organism

• Major Processes
• Food manufacture
• Food transportation
• Food storage
• Growth and development
• Reproduction of its species

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(Plant) Taxonomy

• The Science of the classification of organisms
• Who Needs Those Strange Names Anyway?

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Brief History of Taxonomy

• Adam
• Theophrastus (370-285 BC)
• Carl von Linne (Linnaeus)
• 1707-1778

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Definitions

• Taxonomy -- The science of documenting
  biodiversity.
• Systematics -- The study of diversity
  (taxonomy) and the history of organisms
  and the evolutionary relationships
  between them.

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Kingdoms

• Monera
• Protista
• Animalia
• Plantae
• Fungi

• Monera
• Protista
• Animalia
• Plantae
• Fungi
• Bacteria
• Viruses

5 Kingdom System
7 Kingdom System
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Taxonomy Questions

• What plant is this?
• What is its name?
• What plants grow in this area and why?
• Does this plant have any special/unique
  properties?

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Nomenclature

• System by which plants are named.
• Common names.
• Scientific names.

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Common Names

• Advantages
• Often descriptive
• Easy to pronounce
• Easy to remember
• Familiar to people

• Disadvantages
• No rules -- not consistent
• Applied to various taxonomic levels
• May not exist for some plants

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Scientific Names

• The rules.
• Every plant gets one scientific name.
• The species name is a combination of the generic
  name and a specific epithet.
• Generic names are (typically).
• Singular nouns.
• Often descriptive.
• May be derived from other cultures/languages.
• Commerative of a person or place.

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Scientific Names

• Specific Epithet.
• Names are in Latin.
• Italicized or underlined.
• Names must be accompanied by an author citation.

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Scientific Names

• When a plant is named it must be
• Described in Latin and in the authors native
  tongue.
• Validly published in a scientific journal.

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Scientific Names

• The oldest validly published name is the correct
  name. All others are synonyms.
• When a plant is named, a specimen that serves as
  the reference or model is designated and
  deposited in a recognized herbarium.

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Classification Systems

• Artificial.
• Based on one or a limited number of characters.
• The characters are selected first and the groups
  are assigned based on the characters selected.
• Phenetic or Natural.
• Also based on similarity, but uses many
  characteristics.

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Taxonomic Divisions

• Kingdom
• Division
• Class
• Order
• Family
• Genus
• Species

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Plants - Two Classes

• Gymnosperms
• no fruits, but instead have naked seeds in
  cones.
• All woody and perennial, usually evergreen.
• Ex. Conifers, pines, cycads
• Angiosperms
• flowering plants seeds which are always in a
  fruit.
• Monocots Dicots

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Monocots vs. Dicots

• Dicots
• 165,000 species
• Woody/herbaceous
• Two Seed-leaves
• 4-5 flower petals (sometimes more)
• Net veined
• Definite (in a ring) vascular system

• Monocots
• 50,000
• Herbaceous (mostly)
• One Seed leaf
• 3 flower petals (or multiples of 3)
• Parallel veined
• No definite (comlex arrangement) vascular system

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Monocot Leaf Veins

• Veins are Parallel to each other

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Dicot Leaves (Broad-Leaf) Veins

• The veins are in a net-like pattern
• Leaves are NOT necessarily broad

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Monocot Vascular System
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Monocot stem vs. Dicot Stem
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Dicot Vascular System
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CONDUCTIVE TISSUE IS ON THE OUTER PERIMETER OF A
DICOT
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What Makes a Plant

• Leaves
• Roots
• Stems
• Flowers

• Fruit
• Seeds
• Cellulose Cell Walls

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Plant Organs

• The Leaf
• Is a flattened or extended portion of the stem.

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Plant Organs - The Leaf

• 2 basic parts - the blade and the petiole.
• Veins appear as lines or ridges
• Leaves have buds at the base where attach to
  stem

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Plant Organs

• Leaf Types
• Simple
• Compound
• Palmately
• Compound

Pinnately compound
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Double Compound Leaf
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Plant Organs - The Shoot

• Consists of stems and leaves.
• The shoot functions primarily in support, food
  and water conduction, and food manufacture
  (when green).
• Active growing points produce hormones, guiding
  plant growth form.
• Sometimes also stores food.
• Can root at nodes (forms adventitious roots).

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What Makes a Plant

• Leaves
• Roots
• Stems
• Flowers

• Fruit
• Seeds
• Cellulose Cell Walls

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Plant Organs - The Root

• Do not possess nodes, internodes or buds.
• Function primarily in support, and water and
  mineral uptake.
• Grow in both length and diameter as the plant
  grows.
• Commonly grow to 2-3 times the diameter of the
  shoot area primarily in top 12-18 inches of
  soil.
• Must have both water AND air to survive.

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Adventitious Roots
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Root hairs are specialized cell extensions, which
greatly increase the surface area for water and
nutrient uptake.
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• The trees on the right have were inoculate with
  mycorrhiza (a fungus) and symbiotic assocation
  has developed.
• Note the control plants on the left which are
  the same age, but were not inoculated.

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Mycorrhiza
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• Nodules
• are a result of a bacterium living in the roots
  in a Symbiotic relationship.
• Both organisms benefit, roots receive nitrogen
  and the bacterium gets shelter.

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What Makes a Plant

• Leaves
• Roots
• Stems
• Flowers

• Fruit
• Seeds
• Cellulose Cell Walls

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What Makes a Plant

• Leaves
• Roots
• Stems
• Flowers

• Fruit
• Seeds
• Cellulose Cell Walls

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Stem Types

• Bulb
• A bulb is a very short stem wrapped in thickened,
  fleshy bulb scales, which are modified leaves
• Corm
• The corm is an underground stem that is short,
  thickened and fleshy

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The Stem

• Rhizome
• Perennial stems, usually horizontal in position.
  They have nodes and internodes.
• Tuber
• The tuber is a much enlarged and swollen portion
  of an underground branch

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What Makes a Plant

• Leaves
• Roots
• Stems
• Flowers

• Fruit
• Seeds
• Cellulose Cell Walls

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Flower Parts
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Flowers

• Perfect
• Imperfect
• Monecious
• Dioecious

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Flower Parts

• Stamens
• male reproductive organs (produce pollen) contain
  the Anther and Filament.
• Pistil
• female reproductive organs (receive pollen)
  contains Stigma, Style and Ovary, eventually
  forms the fruit/seed.

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Inflorescence Types

• Single
• One Flower
• Cluster
• Three or more flowers gathered closely together
  in simple or branched groups

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Inflorescence Types

• Spike
• Like a raceme, but the flowers lack pedicles.
• Spadix
• A type of spike.

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Inflorescence Types

• Head
• Similar to umbels, but sessile flowers are very
  close together.

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Flower Parts

• Stamen
• (male)
• Pistil
• (female)

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Monoecious Plants have separate male and female
flowers on the same plant.
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Monoecious
This is banana The first flowers are Female The
next flowers are Sterile The last flowers are
Male This prevents self-pollination
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Dioecious Plants have separate male and female
plants.
Female cycad
Male cycad
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Which is Male, Which is Female?
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Perfect Flowers

• Have both male (stamens) and female (pistol)
  parts on the same flower
• Usually have a mechanism to prevent self
  -pollination

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Water Lilly is a perfect flower, How does it
prevent self pollination?
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Lilies are a perfect flower
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CORN IS A WIND POLLINATED FLOWER
THE TASSEL IS THE MALE FLOWER WHICH PRODUCE
POLLEN
The SILK IS THE STIGMA OR FEMALE FLOWER
STRUCTURE
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GRASSES ARE IDENTIFIED BY MINUE STRUCTURES
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What Makes a Plant

• Leaves
• Roots
• Stems
• Flowers

• Fruit
• Seeds
• Cellulose Cell Walls

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Seeds

• Have an outer coat, usually tough (like an egg
  shell).
• Typically have endosperm (like egg white).
• Have one or two inner embryos (like egg yolk).
• Range in size from dust-sized to Avocado-sized.
• Contains one or two cotyledons, or seed-leaves.
• Monocot - one cotyledon - grasses, sedges, palms.
• Dicot - two cotyledons - broadleaves

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Seeds
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.
Spores are not seeds!
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Fruits and Seeds

• Fruits are the ripened and seed-bearing ovaries
  of flowers.
• Fruits are nearly as varied in color, form, size,
  texture and number as are flowers.
• Can be used as the distinguishing characteristic
  of a species or variety.
• Fruits are divided into two large categories
• Dry
• Fleshy

So basically fruits/seeds came from pregnant
flowers!
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Dry Fruits 1

• Achene
• Small hard, indehiscent, one-cavitied, one-seeded
  fruit with thin, almost inseparable wall.
• Samara
• Indehiscent, one or two-seeded winged fruit.

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Dry Fruits 2

• Nuts
• Hard shelled, usually one-seeded indehiscent
  fruits.
• Grain
• One-seeded indehiscent fruit of most grasses,
  including the cereals.

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Dry Fruits 3

• Capsule
• Dehiscent fruit composed of two or more carpels,
  generally with several or many seeds in each
  carpel.
• Silique
• Several-seeded fruit with two carpels.

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Dry Fruits 4

• Legume
• Pod formed from a single pistil, dehiscent along
  both sides
• Follicle
• Several-seeded fruit formed from a single carpel
  and splitting open along one side only.

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Fleshy Fruits

• Are usually juicy and brightly colored,
  contrasting with their backgrounds to make them
  more noticeable to animals.
• All fleshy fruits are indehiscent and
  considerable fleshy tissue is developed as the
  ovary changes into the fruit.

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Fleshy Fruits 1

• Dupe
• Stone fruit, a simple fruit produced from a
  single carpel, usually one-seeded.
• Berry
• One or more carpels developed with a thin
  covering.

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Fleshy Fruits 2

• Pepo
• Berry-like fruit of large size, with tough or
  very firm and hard outer wall.
• Hesperidium
• Berry-like fruit of citrus spp. With numerous oil
  glands.

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Fleshy Fruits 3

• Pome
• Fruit developed largely from the receptacle which
  surrounds the carpels or inedible core parts.
• Aggregate
• Fruit developed from the receptacle of a single
  flower.

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Fleshy Fruits 4

• Multiple
• Fruits derived from many closely clustered
  flowers.

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What Makes a Plant

• Leaves
• Roots
• Stems
• Flowers

• Fruit
• Seeds
• Cellulose Cell Walls

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Plant Types

• Woody
• Herbaceous

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Plant Types

• Annual
• Biennial
• Perennial

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Vascular System

• Xylem
• water-carrying vessels - move water upward from
  roots to stomata
• Phloem
• sap-carrying vessels - moving manufactured
  carbohydrates, hormones, etc., within the plant.
• Xylem and Phloem are paired together in either
  bundles or rings

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Stomata

• Pores in leaves and stems which allow gas
  exchange and escape of water vapor.
• Opening membranes actively transport potassium
  across to build up the osmotic pressure inside of
  the stomatal guard cells, causing them to swell
  with water and open the stomatal pore
• Closing is done by removing potassium.

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Growth FactorsEnvironment

• Water
• Light
• Temperature

• Air
• Pests
• Culture

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Growth Factors - Genetic

• Family
• Species
• Variety
• Cultivar (Cultivated Variety)
• Seed Source - Ecotypes

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Urban Factors InfluencingGrowth

• Pruning
• Staking
• Spacing
• Soil Compaction
• Pollution
• Light
• Nutrition

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Factors Influence Plant Growth

• Genotype (Genes) Environment Phenotype
  (what you see)

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Why Are These Trees Small?
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Genotype (Genes) Environment Phenotype
(what you see)
Genes tell this plant to become a large
tree Environment for the roots is highly
restricted Phenotype small scale version of the a
full sized tree
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Plant Growth Factors

• Genetic
• Plant Family
• Species
• Seed Source

• Environmental
• Water
• Air
• Light
• Temperature
• Pests
• Culture

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Urban Factors InfluencingGrowth

• Pruning - can trigger new growth
• Staking - can weaken tree structure
• Spacing - can modify growth form
• Soil Compaction - can inhibit growth
• Pollution - can inhibit growth or damage plants.

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Pittosporum with lots of room to grow
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Many pittosporum with little room to grow
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How A Plant Grows

• Photosynthesis - to put together with light
  occurs only in green cells
• light ?
• 6CO2 6H2O -----------gt C6H12O6 6O2
• Respiration occurs in ALL living cells
• C6H12O6 6O2 ---gt 6CO2 6H2O Heat

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Plant Growth

• Photosynthesis
• Produces food
• Energy is Stored
• Occurs in Cells with Chloroplasts
• Oxygen is released
• CO2 is used
• Occurs in Sunlight

• Respiration
• Uses food for Energy
• Energy is released
• Occurs in all cells
• Oxygen is used
• CO2 is produced
• Occurs in Dark or Light
• Water is produced

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Stomata
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Plant Hormones
Apical dominance, gavitropism, phototropism,
vascular differentiation, inhibits abscission,
stimulates ethylene synthesis, inhibits (or
promotes) flowering, stimulates fruit development
(parthenocarpic fruit), induces roots on
cuttings Apical dominance, shoot growth, fruit
devel. Fruit ripening, leaf and flowers
senescence, abscission Flower stimulation in long
day plants, shoot elongation Stomatal closure,
abscission, dormancy

• Auxin
• Cytokinin
• Ethylene
• Gibberellin
• Abscisic Acid

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Hormones - Auxins

• 1. Promote shoot and root elongation causes
  cells to elongate somewhat when at low
  concentrations.
• Promote root initiation extremely high levels
  will cause primordial roots in stems to develop
  (similar to building concentrations of auxin in
  the basal region after cutting).
• 3. Inhibit lateral bud break natural auxin
  levels inhibit lateral bud break, but removing
  the auxin-producing bud will allow lateral buds
  to develop.

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Hormones - Gibberellins

1. Cause cell elongation
2. Promote bud break (especially in sudden exposure
   light)
3. Promote seed germination (also in response to
   light)
4. Can cause parthenocarpic (seedless) virgin
   fruit development

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Hormones - Cytokinins

1. Cause cell division
2. Can cause wound sealing and formation of corky
   tissue
3. Stimulates formation of callus (meristematic
   tissue - used in tissue culture)
4. Decreases plant aging and stimulates use of
   nutrients.
5. Promotes lateral bud development in dicots.
6. Promotes chloroplast development

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Other Hormones - Ethylene

• Ethylene
• Promotes aging of plants and plant parts.
• Promotes flowering
• Promotes ripening of fruit
• Abscisic Acid
• Inhibits cell formation and growth
• Causes the formation of abscission layers in
  petioles and fruit peduncles, causing leaf drop
  and fruit drop.

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Plant Responses to External Factors

• Gravity
• plants grow shoots upright and roots downward in
  response to gravity, called gravitropism.
• Light
• Phototropism
• Leaf shape/structure/size shade leaves are
  larger, thinner, contain fewer chloroplasts. Sun
  leaves are smaller, thicker, contain more
  chloroplasts
• Leaf response to altering light levels Sun
  leaves will drop off in shade due to inadequate
  harvesting of light. Shade leaves will drop off
  in sun due to burning out of systems from
  overload in light levels.
• Bud break
• Seed germination

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Gravitropism
These plants are exhibiting gravitropic response
a due to the force of gravity and the plant
hormone auxin.
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Phototropism
Auxin is responsible for causing the plant to
bend towards the light.
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Apical Dominance
The plant produces auxin at the tips, once the
plant tip is removed dormant lateral buds are no
longer inhibited.
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Apical Dominance
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Palms

• One Growing Point

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Plant Rooting
Auxin induces rooting on plant cuttings. We can
supplement auxin with synthetic auxin rooting
compounds
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Gibberilic Acid Causes cell elongation. This
bunch of grapes was sprayed was sprayed with the
hormone.
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Gibberilic Acid

• In Camellias
• Promotes earlier flowering
• Causes flowers to be larger than typical

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Ethylene
Causes fruit to ripening Responsible for leaf
abscission Causes leaf and flower senescence
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Phytochrome
Plant pigment which perceives certain wavelengths
of light Many seed need light for
germination Timingmechanism for plants
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Some plants exhibit and juvenile state... and
an adult state. The phase change is not always
so easy to distinguish.
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Descriptive Classifications

• Climatic Adaptation
• Tropical
• Subtropical
• Temperate

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We are in zone 9a
Tropical plants can not tolerate frost and need
to be in zone 10 were frost is rare or 11 which
is frost free.
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Grafting aligns the cambium layers of two plants.
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Tissue Culture

• Can Produce MANY genetically identical plants
  quickly and cheaply

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Undifferentiated Plant Cells
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Mistletoe is clearly a parasite. Note how it
invades its host.
Eventually the plant is weakened and dies.
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Ball moss it epiphytic too.
Spanish Moss is an Epiphyte using the tree for
support only and does NOT rob it of nutrients!
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Many plants use trees for support only, while it
might weight down the tree it will not cause the
tree harm.
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Botany and Taxonomy

• Original concept and text by Bruce Ide, Palm
  Beach County.
• Additional text and pictures by Jim Moll,
  Hernando County.