Transcript Cabell County Master Gardener Association, Inc.

Basic Botany
Cabell County Master Gardener Association, Inc.
Prepared by Steve Beckelhimer
[email protected]
Eukaryotes
• Living things whose cells have a nucleus
• Includes plants, animals, fungus and protists but not
bacteria
Classification
• Animals
o Kingdom
o Phylum
o Class
o Order
o Family
o Genus
o Species
• Plants
o Kingdom
o Division
o Class
o Order
o Family - aceae
o Genus
o Species
Gymnosperm/Angiosperm
Gymnosperm
• Naked seed
• Seeds not enclosed in a fruit
• Includes conifers and a few others
like gingko
• Ancient group
Angiosperm
• Covered seed
• Seeds encased in an ovary (fruit)
• Most common plants are
angiosperms
• Considered more advanced
Monocot/Dicot
Monocot
Dicot
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One seed leaf
Parallel leaf veins
Flower parts in threes
Fibrous roots
Two seed leaves
Branched leaf veins
Flower parts in fours or fives
Tap roots
Nomenclature
Scientific Names
• As with all living things, the scientific names of plants are
composed of two parts (binomial nomenclature), the Genus and
species.
• Examples:
o White oak – Quercus alba
o Red oak – Quercus rubra
o Panda plant - Kalanchoe tomentosa
o Virginia creeper - Parthenocissus quinquefolia
o Witch hazel - Hamamelis virginiana
o Sugar maple – Acer saccharum
o Box elder – Acer negundo
Common names
• Often confusing
• Very different plants may have the same name in different areas (silver
maple, water maple, creek maple, silverleaf maple, soft maple, swamp maple,
or white maple)
• The same plant may have very different names in some localities
• For example, the European white waterlily has at least 245 different names
Parts of a Plant
Root system
• Penetrates soil
• Absorbs water and ions
• Anchors plant
Shoot system
• Stems: serve as framework to position leaves
• Leaves: primary location for photosynthesis
• Flowers and fruit: serve reproductive functions
Vegetative
Sexual
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• Flowers
• Fruits
• Seeds
Leaves
Stems
Buds
Roots
Stems
Stems transport materials between
roots and leaves
• Phloem – carries sugars produced in leaves to the roots
and fruits for storage
• Xylem – carries water and minerals from the roots to
shoots
• Cambium – growth tissue that is found between xylem &
phloem
Monocot Stem
Dicot Stem
Woody Dicot Stem
Stem Parts
Stem Modifications
Leaves
Function of Leaves
• Collect sunlight
• Carry out photosynthesis
Leaf Parts
Simple/Compound Leaves
Leaf Shapes
Leaf Venation
Leaf Tips
Leaf Bases
Leaf Margins
Leaf Arrangements
Buds
Leaf/Flower Buds
Bud Position
Roots
Root system
• Penetrates soil
• Absorbs water and ions
• Anchors plant
Tap/Fibrous Roots
Root Structure
Flowers
Functions of Flowers
• Produce seeds and the mechanisms for distribution
• Attract pollinators or distribute pollen
Male/Female/Complete Flowers
• Complete Flowers - flowers that have male and female
parts
• Pistillate Flowers – flowers that have only functional
female parts
• Staminate Flowers – flowers that have only functional
male parts
Monoecious and Dioecious Plants
• Hermaphroditic plants have all flowers with both male and female parts.
• Dioecious plants have male (staminate) flowers on one plant, and female
(pistillate) flowers on another plant.
• Monoecious plants have separate male and female flowers on the same
plant.
• Male and female flowers may be produced at different times in monoecious
plants.
Inflorescence Patterns
Fruit
Fruits
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Fruits consist of ovules (seeds) and ovary walls
Some fruits are composed of many ovaries
Fruit originates from the pistillate part of the flower
May be classified as simple, aggregate or multiple fruits
Simple/Multiple/Aggregate Fruit
Seeds
Seeds in Plant Reproduction
• Seeds contain everything that the embryonic plant needs to grow
when conditions are right
• Most of the weight of the seed is endosperm, a starchy material
that, when conditions are right, can be converted into sugar to
grow the plant
• One hormone keeps the embryo in dormancy
• This hormone is more water soluble than another hormone that
stimulates growth
• In favorable temperatures and in the presence of water, the
growth hormone overtakes the dormancy hormone and
germination begins
Seed Structure
Germination
Radish Quiz Onion
Carrot
Tomato
Parsnip
• Stem
Cabbage
• Leaf
Apple
• Fruit
Cucumber
Spinach
• Root
Potato
Brocolli
• Flower
Avocado
Beans
• Seed
Asparagus Corn
Photosynthesis
Photosynthesis Captures Energy
• Light energy is used to combine molecules of
carbon dioxide from the atmosphere and water
from the soil to form the simple sugar, glucose
giving off oxygen as a waste product
• Overall reaction of photosynthesis
CO2 + H2O  C6H12O6 + O2
Leaves are ideal for the process
• Photosynthesis primarily takes place in the mesophyll tissues of
leaves where chlorophyll is abundant, veins bring water and air
spaces allow gas exchange
• Openings (Stomata) on the undersides of leaves allow carbon
dioxide in and oxygen to escape
• Guard cells open and close to control the movement in and out of
the leaf’s internal air spaces
• Leaves can move to track the sun like efficient solar panels
Photosynthesis Limitations
• Photosynthesis occurs only between 46o and 113o F
• Violet light provides most light for photosynthesis and
green light provides the least
• An abundance of oxygen is toxic to plants
Respiration
Plants need energy too
• It is a myth that plants do not need to carry out respiration or that they only do
respiration at night
• Although plants produce carbohydrates through photosynthesis, they harvest the
energy through respiration in usable forms
• In some ways, respiration can be thought of as the reverse of the photosynthetic
process although the metabolism and structures are very different
• Overall reaction of respiration
C6H12O6 + O2  CO2 + H2O
Comparison
Photosynthesis
Respiration
• Produces carbohydrates
• Light energy is stored as
chemical energy
• Occurs cells with chloroplasts
• Oxygen is released
• Water is used
• Carbon dioxide is used
• Breaks down carbohydrates
• Chemical energy is converted
to energy for cells
• Occurs in all cells
• Oxygen is used
• Water is released
• Carbon dioxide is released
Transpiration
Movement of Water & Minerals
• An abundance of water exists surrounding the roots of plants
while water is used for photosynthesis in the leaves of plants
• Although photosynthesis uses water, far more water is evaporated
(transpired) from the leaves of plants than is used for
photosynthesis
• Xylem carries the water from the source (roots) to the sink (leaves)
• Water is carried in a plant through passive processes and is not
pumped
• Opening and closing of stomata control the rate of transpiration
Stomata control Transpiration
Plant Life Cycles
• Annual– plants complete cycle (germination, vegetative growth,
seed production and dispersal) in a single year
• Perennial – vegetative parts of plants survive from year to year
and may or may not reproduce each year
• Biennial – two years are required to complete the life cycle.
Typically vegetative growth takes place the first year and sexual
reproduction occurs the second year. Plants may die after
reproduction.
Plant Growth &
Regulation
Chemical Nature of Hormones
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Chemical substances produced in small quantities in one location
Transported to another location to effect physiological response
Response can be stimulatory or inhibitory
Animal hormones produced at definite sites, organs of hormone
production
• Plant hormones are not produced in such specialized tissues
Five major kinds of plant hormones
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Auxin
Cytokinins
Gibberellins
Ethylene
Abscisic acid
Auxin
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Controls growth of lateral buds on stem
Regulates stem elongation
Produced in terminal buds
Results in the cone shape of plants
Chemically similar to tryptophan
Synthetic auxin is used to promote
flowering and rooting
• Concentrations of synthetic auxin can be
herbicidal
Cytokinin
• Promotes cell division and differentiation in combination with
auxin
• Mostly produced in roots and transported throughout plant
• Chemically derived from adenine
Gibberellin
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Synthesized in apical portions of stems and roots
Promotes internodal elongation, enhanced by auxin
Restored normal growth to dwarf plant mutants
Stimulates hydrolytic enzyme production in germinating
seeds
Ethylene
• Suppresses lateral bud formation when combined with
auxin
• Suppresses stem and root elongation
• Primary factor in formation of separation layer in
abscission (opposite of auxin) causing leaf drop
• Produced in large quantities during fruit ripening
Abscisic acid
• Involved in leaf drop from processes other than seasonal
senescence
• Influences formation of winter buds
• Suppresses growth of dormant lateral buds
• Controls opening and closing of stomata
Tropisms
Phototropism
Auxin moves to a less
well lit side of a plant
causing elongation on
one side and a
temporary bending of
the plant
Gravitotropism
• Differential in auxin
concentration
develops in
horizontal stems
• More auxin on lower
side causes these cells
to elongate, stem rises
Thigmotropism
• Response of plants to touch
• Causes curling of tendrils, twining of vines
• Action associated with rapid cellular growth or changes in turgor
pressure
• Coiling of tendrils is associated with auxin and ethylene
• Examples include touch-me-not and Venus fly trap
Thank you
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Much material for this presentation was taken from the West Virginia
Master Gardener Handbook