Transcript botany_plantphys_2008

Cory Tanner
Consumer Horticulture Agent/Master Gardener
Coordinator
Terminology
Botany: the science of plants
Anatomy: internal structure
Morphology: external structure/form
Taxonomy: the classification of plants
Physiology: study of plant growth and
development
Vascular Plants
Ferns
Cone Bearing
Plants
Flowering Plants
Dicots
Monocots
Terminology
Gymnosperm – “naked seed”
 Has no flower or ovary (fruit); only cones
 All conifers (pines, cedars, arborvitae)
Angiosperm – “vessel seeded”
 Has a flower with an ovary (fruit)
 All flowering plants
 Divided into Monocots and Dicots
Terminology
Dicotyledons (Dicots):
flowering plants that contain two
seed leaves
Monocotyledons (Monocots):
flowering plants that possess one
seed leaf
Monocot
Dicot
Plant Classification
Kingdom
Phylum
Class
Order
Family
Genus
Species
Cultivar
Botanical Names
What’s Wrong with Common Names?
Catesby’s Trillium
or
Rosey Wake-robin
or
Bashful Wake-robin
Trillium catesbaei
Scientific Plant Names
 Binomial Nomenclature – 2-name system
 Genus species
 Developed by Carolus Linnaeus (1753)
 Always Latinized and italicized
 Usually very descriptive of the plant
Scientific Plant Names (cont.)
 Genus – a noun
 identifies a particular group of related plants
 First letter always capitalized
 species – typically an adjective
 identifies a distinct subset of the Genus
 all lowercase
Latin names should always be italicized or underlined.
Scientific Plant Names (cont.)
When two names aren’t enough…
 variety – has traits that separate it from the species, but
not enough to be a new species
 Designated by var.
Cercis canadensis var. alba
 cultivar – “cultivated variety”
 A variety that arose in garden/nursery culture.
 Designated in single quotes with the first letter of each
word capitalized. Not italicized.
Magnolia grandiflora ‘Little Gem’
Scientific Plant Names (cont.)
What about hybrids?
Hybrid – results from cross-pollination between two
different species.
 Designated by an “x” between Genus and species.
Osmanthus x fortunei – Fortune’s Tea Olive
Hybrid between O. heterophyllus and O. fragrans
Plant Parts
Plant parts fall into two
categories:
a) vegetative
b) sexual reproductive
Meristems – regions of plant growth
Apical Meristems (aka Terminal Buds)
• Found at shoot and root tips
• Produce stems, roots, leaves, and lateral buds
• Responsible for shoot/root length (Primary Growth)
Lateral Meristems (aka Vascular Cambium)
• Located laterally along stems and roots
• Responsible for increases in stem/root girth (Secondary
Growth)
Vascular Tissues
Xylem – transports water and mineral nutrients
from roots to stems and leaves.
Phloem – transports sugars (photosynthates) from
leaves to other plant parts. Can move “sap”
up or down.
Xylem and phloem arranged in vascular bundles.
Roots
Functions of Roots:
1. absorption (water and
mineral)
2. structural support
3. storage
Types of Roots:
1. radicle – seed root
2. primary root – tap root
3. lateral root
Root Anatomy
Above Ground
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Stem Parts
Stem Anatomy
Tree Trunk Components
Types of Buds
Vine Morphology
Leaf Parts
blade
midrib
petiole
Leaf Anatomy
Leaf Arrangement
Leaf Types
Leaf Venation
• Venation refers to the pattern in which the veins
are distributed in the leaf blade
• Parallel or Net-veined
• Net-veined can be either pinnate or palmate
Flower Anatomy
Sepals - small, green, leaf-like structures
on the base of the flower
Petals - highly colored parts of the
flower
Stamen - male reproductive parts
Pistil - female reproductive parts
Flower Anatomy
Perfect flower - has a stamen, pistil, petal and
sepals.
Incomplete flower - missing one of the four parts
Complete flower - has a stamen and pistil
Imperfect flower - has either stamen
(staminate) or a pistil (pistillate)
Flower Anatomy
Dioecious - have staminate (male) and
pistillate (female) on separate plants
i.e., hollies.
Monoecious - have male and female flowers
on the same plant i.e., squash and
cucumbers.
Inflorescences: flower arrangements
Pollination
Cross-pollination - pollen from one plant is
transferred to the stigma of another.
Self-pollination - the stigma is pollinated by
pollen from the same plant.
Fertilization - ovule (egg) is fertilized by the
sperm from the pollen grain.
Fruit
An enlarged ovary.
-Simple
-Aggregate
-Multiple
Seed
A mature ovule, that
contains the embryo
and cotyledons (starch
filled food source).
Growth Cycles
Annual: A plant that completes its lifecycle in one growing
season. Winter annuals survive the winter,
summer annuals survive the summer.
Biennial: A plant the requires two growing seasons to
complete its lifecycle.
Herbaceous perennial: A non-woody plant that lives for
several years. It’s shoots die back every winter.
Woody perennial: A tree or shrub
The study of plant growth and development
Primary Plant Processes
Photosynthesis
Respiration
Transpiration
Photosynthesis
Photosynthesis is arguably the most important
biological process on earth. By liberating oxygen and
consuming carbon dioxide, it has transformed the world
into the hospitable environment we know today.
Directly or indirectly, photosynthesis fills all of our food
requirements and many of our needs for fiber and
building materials. The energy stored in petroleum,
natural gas and coal all came from the sun via
photosynthesis, as does the energy in firewood, which is
a major fuel in many parts of the world.
- from “Why Study Photosynthesis?” by. Devens Gust, Ph.D.
Arizona State University - http://photoscience.la.asu.edu/photosyn/study.html
Photosynthetic Reaction
6CO2 + 6H2O
Carbon
Dioxide
Water
Chlorophyll
C6H12O6 + 602
Sugar
Oxygen
Terminology
Chlorophyll – green pigment in plants that
collects solar energy for photosynthesis
Chloroplast – component of plant cells that
contains chlorophyll and is responsible for
photosynthesis.
All green parts of plants have chloroplasts.
Light Absorption by Chlorophyll
Courtesy of Arizona State University
Respiration
The process by which sugars and starches are converted
to energy.
ENERGY
C6H1206 + 6O2
Sugar
Oxygen
6CO2 + 6H2O + Heat
Carbon
Water
Dioxide
Photosynthesis
Respiration
Produces food
Uses food for plant energy
Releases oxygen
Releases energy
Occurs in all cells
containing chlorophyll
Occurs in all cells
Uses water
Uses carbon dioxide
Occurs in light
Uses oxygen
Produces water
Produces carbon dioxide
Occurs in light as well as
dark
Transpiration
The process by which plants lose water (evaporation)
through stomata.
- Responsible for water transport in plants
- Responsible for nutrient transport.
- Cools plant parts through evaporation.
Transpiration
Stomata
Stomata
Water Movement
Transpiration
The amount of water loss from a plant
through transpiration depends on
environmental factors such as temperature,
humidity and air movement.
Guttation
Occurs mainly
at night due to
root pressure.
Nutrient Absorption
How do nutrients get into a root?
• Root Interception
• Mass Flow
• Diffusion
Root Interception
Roots intercept nutrients as they
grow and expand in the soil.
Mass Flow
Moving of large volumes of water,
with nutrients in solution, to the plant
roots, into the plant and to the leaves.
Usually in the transpiration stream.
Diffusion
Movement of nutrients from areas
of high concentration to areas of
low concentration.
Root Absorption
Requires Oxygen and
Energy
A decrease in P.S.
results in a decrease in
root absorption
Factors Inhibiting Nutrient Uptake
Soil Aeration
Nutrient Availability
Soil Temperature
Type of Plant
Soil Moisture
Effects of Other Nutrients
Soil pH
Solubility of Nutrient
Environmental Factors
Affecting Plant Growth
 Light
Temperature
Water
Light
Quantity – amount of light reaching the plant.
Maximum during the summer and minimum during
the winter.
Quality - refers to the color or wavelength that reaches
the plant.
Duration - refers to the amount of time a plant is
exposed to light.
Photoperiod – effect of day length on plant development.
Photoperiod
Short-day Plants - require a period of uninterrupted
darkness to flower. Example: Poinsettia
Long-day Plants – require long-days (short nights) to form
flowers. Example: Black-eyed Susan
Day-neutral – non-responsive to day length. Many plants.
Temperature
Temperature is a factor in flower and fruit production.
- chilling hours in peach production
Excessive heat (> 90o F) can restrict photosynthesis
Plants can be classified as either hardy or non-hardy
depending on their ability to withstand cold
temperatures.
Roles of Water
 Required for photosynthesis
 Involved in plant growth
 Transports mineral nutrients and photosynthates
 Maintains cell turgor (prevents wilting)
 Cools the plant
In Conclusion …
A basic understanding of botany and plant physiology is key
to diagnosing and resolving many plant problems.
You should understand:
 basic plant anatomy
 scientific plant naming
 the processes of photosynthesis, respiration and
transpiration
 how environmental conditions affect plants