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5/29/2009
Basic Botany
by Aileen
Bourne
Part I:
Biological classification
Botany is the study of plants
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Classification or “putting into
groups” is a part of taxonomy
“which is a science
that is used in Botany
(and other life
sciences) to help
make sense of the
large number of living
things in that group.
Carolus Linnaeus is often
called the “Father of
Taxonomy”
He established groupings
based on kinship and..
First used scientific
names
Linnaeus organized living things into
groups that became more and more alike
These groups are called Taxa
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The largest group of organisms is in the
taxa called Kingdom
There are 7 major taxa into which
organisms are placed
They are :Kingdom, Phylum, Class, Order,
Family, Genus, species
Linnaeus divided all the things in the
world into either Plant or Animal Kingdom
The Plant Kingdom has continued to be
one of the major divisions of the living
things.
PLANT Kingdom is
Made up of living things that are
1.photosynthetic (mainly terrestrial)
2.eukaryotes and 3. have cell walls
Or ..can make their own food, have a
nucleus and organelles in their cells and
have cell walls with cellulose in them…
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Kingdoms are further divided into
Phyla or Divisions
Master Gardeners are mostly interested in the
higher plants division…Tracheophytes.
These are the plants with trachea or…”little
pipes” which carry food and water throughout
the plant.
Divisions are divided into classes
Of the tracheophytes we are mostly interested
in class AngiospermaeAngiospermae- fruit covered seeded
plants
Angiosperm are divided into Monocots and Dicots
scitec.uwichill.edu
and class Gymnospermae… and the naked
seeded plants
scitec.uwichill.edu
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Monocot - A subclass of the
Angiospermae in which the plants have
one cotyledon in their seeds, have parallel
leaf venation, and have flower parts in
threes or multiples thereof
Dicot - A subclass of the Angiospermae in
which the plants have two cotyledons in
their seeds, have pinnate or palmate leaf
venation
Typical classification of a red maple
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Category
Name
Characteristics
Kingdom
Plantae
Organisms that usually have rigid cell walls and usually
possess chlorophyll.
Phylum
Tracheophyta
Vascular plants.
Class
Angiospermae
Flowering plants, seed enclosed in ovary.
Order
Sapindales
Soapberry order consisting of a number of trees and shrubs.
Family
Aceraceae
Maple family.
Genus
Acer
Maples and box elder.
Species
Acer rubrum
Red maple.
Physical Geography
Now, from the classification of the red
maple, the genus and species name are
important
They make up the scientific name of a
plant.
Acer rubrum
http://www.cnr.vt.edu/dendro/de
ndrology/syllabus/arubrum.htm
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SCIENTIFIC NAMES ARE MADE UP OF 2 PARTS:
THE GENUS NAME AND THE SPECIES NAME
THE GENUS NAME IS LIKE YOUR LAST NAME … as Jones
THE SPECIES NAME IS LIKE YOUR FIRST NAME …as Gregory
Acer
rubrum= maple, red
Genus name
Places the plant in a
particular group
As maplemaple-box elder
group
This group may have
several plants in it
www.extension.umn.edu/
Species name
Tells exactly which
one of several in a
genus group we are
talking about
This is the most
specific group
Only 1 plant type
www.extension.umn.edu
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The term species means “kind ofof-”.
A more technical definition of species is a group
of interbreeding organisms that do not ordinarily
breed with members of other groups and who
produce offspring that can also reproduce.
So…a species is 1 kind of living thing.
Common names
Can be confusing :
www.nawwal.org
www.aristov.com/photo/flower
Some plants have the same common name
Some plants have no common name
Some plants have more than one common
name
Common names differ from place to place
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Plant scientific names…
Are the only way to communicate which
plant you mean
-in any culture
-in any location
Makiko
Scientific names are rather fun if
you learn a few ways to know how
they are used and how they are put
together.
1. the genus name is Capitalized and
either underlined or italicized
2. the species name is not capitalized, but
it is underlined or italicized
Ex. Cornus florida =flowering dogwood
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Various methods are used to pick the
genus and species names
Adjectives are often used
Classical Latin names are used
Greek names are sometimes used
Names from Latin or Greek myths are
used
A. Examples of adjectives:
Magnolia virginiana, "Virginian magnolia"
(sweet bay);
Camellia japonica, "Japanese camellia;",
Quercus alba, "white oak;“
Pinus palustris, "swamp pine" (longleaf
pine."
These adjectives must match the genus
name in gender, number, and case.
SOME LATIN TERMS used as adjectives
see site below or MG manual p 8 for many more
acaulis = stemless
alba = white
barbata = bearded, hairy
canadensis = from Canada
digitata = (leaves) like a hand, with five lobes
edulis = edible
flava = yellow
hirsuta = hairy
http://theseedsite.co.uk/latin.html
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B.Classical Latin plant names, sometimes
transferred by modern botanists to other
plants:
Quercus (oak)
Rosa (rose)
Pinus (pine)
Acer (Maple
C. Classical Greek plant names, sometimes
transferred by modern botanists to other plants:
Rhododendron (rhododendron, azalea)
Narcissus (daffodil)
Thuja (arbor vitae)
Carya (hickory)
Typha (cattail)
Zea (corn)
D. Names from Latin and Greek myths,
are taken over by recent botanists for
plant names:
Nyssa (tupelo, gum)
Andromeda (andromeda)
Liriope (monkey grass)
Iris (iris).
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Besides the genus and species names
there are often other distinctive names
added to scientific names
Buxus microphylla var. japonica is the
name for the variety of Japanese
boxwood
Cornus florida 'White Cloud' is the name
for a cultivar of flowering dogwood
A variety is a group of plants in a natural
population that has distinctive features. A
variety is propagated sexually and comes
true from seeds.
The varietial name is added after the name
of the species and is preceded by the
abbreviation "var."
For example, Buxus microphylla var.
japonica is the name for the variety of
Japanese boxwood
http://www.ces.ncsu.edu/depts/hort/consumer/quickref/general/scientific_names.html
A cultivar is a plant selected by man for one or more unique traits
and usually is propagated vegetatively in order to maintain those
traits.
If a new type of tomato was developed by cross pollination in a
breeding program, it would be a cultivar.
A cultivar name follows the species name and is
enclosed within single quotation marks, not underlined
or italicized, and each word begins with a capital letters.
Cornus florida 'White Cloud' White Cloud
http://
flowering dogwood
www.ces.ncsu.edu/depts/hort/consumer/quickref/general/scientific_names.html
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Keys
These are wonderful ways of finding out
what your plant is, if you do not know.
“keys” are usually found in book form
They make use of particular features to
identify the plant you may not know
MAKING A
DICHOTOMOUS KEY
Here are two examples
of keys to show how to
key out organisms, such
as a kangaroo, a cow, a
bee and a spider. Shown
are a branching key
and a numbered key.
key.
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Animals to be keyed out
(Kangaroo, Cow, Bee and
Spider)
No internal Skeleton
Internal skeleton
(Bee & Spider)
(Kangaroo & Cow)
Six legs
(Bee)
Not six legs
(Spider)
Pouch present
(Kangaroo)
Pouch absent
(Cow)
Numbered key
1a. Internal skeleton……………………go to
21b.
No internal skeleton……………………go to 3
2a. Pouch present……………………kangaroo
2b. Pouch absent……………………cow
3a. Six legs……………………bee
3b. Not six legs……………………spider
Example:
Main Key for plants of the Virginia Coast Reserve LTER
compiled by Dave Richardson
1a. Woody plants.
2a. Erect trees and shrubs.
3a. NeedleNeedle-like leaves.....
leaves.....see
see Subkey I.
I.
3b. Broad leaves.
4a. Opposite leaves.
5a. Opposite compound leaves.....see
leaves.....see Subkey II.
II.
5b. Opposite simple leaves.....see
leaves.....see Subkey III.
III.
4b. Alternate leaves.
6a. Alternate compound leaves.....see
leaves.....see Subkey IV.
IV.
6b. Alternate simple leaves.....see
leaves.....see Subkey V.
V.
2b. Vines and brambles.....see
brambles.....see Subkey VI.
VI.
1b. NonNon-woody plants.
7a. Vines and brambles.....see
brambles.....see Subkey VI.
VI.
7b. Other herbaceous plants.
8a. Leaves linear with parallel veins and bladeblade- hairhair- or needleneedle-like in shape; flowers indivually inconspicuous.
9a. Plants terrestrial or at least not totally aquatic and not usually fully submerged (Grasses, Sedges, and Rushes).
10a. Stem triangular, mainly solid, without joints.....see
joints.....see Subkey VII.
VII.
10b. Stem round.
11a. No branches in inflorescence (look close to make sure it doesn't just have branches that are
atlantic.evsc.virginia.edu
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Part II:
Plant parts and function
2 categories of plant
parts
1. vegetative parts
Roots
Stems
leaves
2. sexual parts
flower buds
flowers
fruit
seeds
Roots:
Function
1. anchor plant
2. absorb water and minerals
3. transport food and water
4. store food
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There are two major types of root systems
in plants:
Taproot systems have a stout main root
with a limited number of sideside-branching
roots.
Fibrous root systems have many, finely
branched roots
dandelion -taproot
foxtail
foxtail--fibrous
/www.hcs.ohio
www.hcs.ohio--state.edu:
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Internal root
root's epidermis is its outermost layer of
cells (Figure 3). These cells are
responsible for absorbing water and
minerals dissolved in water. Cortex cells
are involved in moving water from the
epidermis to the vascular tissue (xylem
and phloem) and in storing food. Vascular
tissue is located in the center of the root
and conducts food and water
Root hairs are small hairhair-like
extensions of the outer layer of
root CELLS. Roots can have an
amazingly large number of root
hairs. Root hairs increase the
surface area of the roots,
increasing the capacity to absorb
nutrients and water.
Root hairs greatly increase the
surface area of roots.
Root
hairs absorb nutrients and water.
Root hairs are often destroyed
when a plant is dug from the soil.
New root hairs will quickly form as
long as the roots themselves are
undamaged
The roots of many wild plants and nearly all woody
plants are associated with special kinds of fungi called
MYCORRHIZAE. The fine threads of fungus grow around
and often into the roots, replacing the root hairs. The
fungus gets sugar from the plant and supplies it with
water and nutrients.
Other plants, particularly in the bean family form root
nodules. These contain bacteria that take nitrogen from
the air and convert it to fertilizer for the plant. A few
other plants such as alder also form nitrogen fixing
nodules.
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micorrhiza
nodules
Stems
Stems are generally upright and above ground,
easy to locate and identify. However, many
stems grow below ground or are groundgroundhugging. A modified stem is recognizable
because it includes buds and sometimes leaves.
Buds and shoots generally develop on stems.
They carry nutrients and water from the roots to
the other parts of the plant.
In some cases, stems also store food.
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functions
They carry nutrients
and water from the
roots to the other
parts of the plant.
They also hold the
leaves up to the light.
In some cases, stems
also store food.
Nodes are places on the stem where leaves are
attached and buds form.
Roots often form at nodes of creeping plants
and when cuttings are taken for propagation.
Internodes are the segments of the stem
between nodes.
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The quality and amount of available light and temperature affect the length of
the internode. The distance between nodes can be long or short. This distance
reflects growing conditions. Plants grown under poor light conditions may be
spindly, with very long, thin, and weak internodes
Stem Terminology
- Shoot -A young stem (1 year old or
less) with leaves.
Twig -A young stem (1 year old or less)
that is in the dormant winter stage (has
no leaves)
Branch -A stem that is more than 1 year
old, typically with lateral stems radiating
from it.
Trunk -A woody plant's main stem.
There are many stem variations in plants. Some variations are used
as food, such as potatoes and asparagus. Others are sold in
dormant condition for planting in the landscape, such as crocus
corms and tulip bulbs. Many stem modifications provide
opportunities for PROPAGATION.
a bulb has a flattened stem at the base with fleshy leaves making
up most of the structure
a corm is an upright swollen stem, often enclosed in papery leaves
a stolon is a stem that grows along the ground suface, such as a
strawberry runner
a rhizome is a horizontal underground stem, such as in bent grass
or some irises
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a bulb has a flattened stem at the base with
fleshy leaves making up most of the structure
a corm is an upright swollen stem, often
enclosed in papery leaves
a stolon is a stem that grows along the ground
surface, such as a strawberry runner
a rhizome is a horizontal underground stem,
such as in bent grass or some irises
Corm of Gladiolus
rhizomes of Jerusalem artichoke
http://www.hcs.ohiohttp://www.hcs.ohiostate.edu:16080/mgonline/Botany/
One of the major functions of the stem is to
move water, nutrients, and food through the
plant. The internal tubes in stems act like the
plumbing in a house or the blood vessels in
people. As in humans, this system is called the
vascular system.
The foodfood-moving part of the vascular system is
called the phloem (from leaves to roots)
The waterwater-and
and--mineralmineral-moving system is called
the xylem (from roots to leaves)
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Cs sunflower
www.hcs.ohio--state.edu
www.hcs.ohio
Meristems
There are two areas of cell division or MERISTEMS
contributing to the growth of a stem. The apical
meristem at the tip increases the length of stem and
produces new leaves and buds. The other meristem is
the CAMBIUM that produces new phloem and xylem. In
most plants (DICOTS) this is a ring of cells that increases
the girth of the stem. In plants such as lilies and grasses
(MONOCOTS) the cambium is scattered through the
stem and does not remain active, so they cannot
increase in girth
Injury
to the cambium layer in certain plants can kill the entire plant.
For example, trees can be killed by
GIRDLING damage to the cambium layer located just inside the bark.
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Names for stems based on how long it lives:
1. perennial lives more than 2 years.
2. annuals pass through their whole life cycle in
one growing season
3. biennials use a 2 year growing season.
Leaves
Leaves are lateral outgrowths from the stem,
most commonly flat, broad, and green. This
maximizes their function of absorbing sunlight
and transforming it into food. Leaves have
evolved into many shapes and sizes, reflecting
adaptations to the environment. Leaves
generally consist of a stalk or PETIOLE and a
blade or LAMINA. In simple leaves the lamina is
in one piece. In compound leaves several
pieces of lamina are joined to one petiole
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Leaf arrangement
Leaf arrangement
Alternate
Whorled
www.pssc.ttu.edu
opposite
basal
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The first leaves to appear when the seed
germinates are often the seed leaves or
cotyledons ).
There can be only one (in MONOCOTS), two (in
DICOTS) or many cotyledons (in conifers).
Jewel weed (a dicot) , spiderwort ( a monocot)
Jewel weed (dicot)
//www.hcs.ohio--state.edu
//www.hcs.ohio
spiderwort (monocot)
Specialized leaves
SPINES function to protect the plant (eg.
barberry).
TENDRILS support the stems
of climbing plants
BRACTS are leaves
associated with flowers; they may be
green or brightly colored and mistaken for
petals
Scale leaves provide protection
for buds and can be further modified for
food storage to form a bulb
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www.hcs.ohio--state.edu:
www.hcs.ohio
Buds are undeveloped shoots and flowers. Buds are classified
terminal or lateral. Another term for terminal is apical. Terminal
buds can be identified by their location at the tip of a stem. Lateral
buds are located at the sides of the stem.
Flower buds are normally larger than VEGETATIVE buds. Cabbage
and head lettuce are examples of very large terminal buds. Brussels
sprouts are edible lateral buds. Broccoli is an example of edible
flower buds
remaining type of bud, ADVENTITIOUS
(ad
(ad--venven-TISH
TISH--us), forms at any other
location. Adventitious buds may form on
the internode of the stem, at the edge of
a leaf or at the cut on a stem or root.
Stem and leaf cuttings can develop
adventitious buds which also send down
roots to form a complete new plant
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Flower
The Flower:
The flower is the reproductive unit of
some plants (angiosperms). Parts of the
flower include petals
petals,, sepals
sepals,, one or more
carpels (the female reproductive organs),
and stamens (the male reproductive
organs).
www.urbanext.uiuc.edu
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Female Reproductive
Organs:
The pistil is the collective
term for the carpel(s).
Each carpel includes an
ovary (where the ovules
are produced; ovules are
the female reproductive
cells, the eggs), a style (a
tube on top of the ovary),
and a stigma (which
receives the pollen during
fertilization
She’s a Pistil
packin’ mama
she’s got Stigma,
she’s got Style.
The Male
Reproductive
Organs:
Stamen
Stamenss are the male
reproductive parts of
flowers. A stamen
consists of an anther
(which produces
pollen) and a
filament. The pollen
consists of the male
reproductive cells;
they fertilize ovules.
Types of Flowers:
Some flowers (called perfect flowers)
flowers) have both male
and female reproductive organs; some flowers (called
imperfect flowers)
flowers) have only male reproductive organs
or only female reproductive organs. Some plants have
both male and female flowers, while other have males
on one plant and females on another.
Complete flowers have stamens
stamens,, a pistil
pistil,, petals
petals,, and
sepals..
sepals
Incomplete flowers lack one of these parts.
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Inflorescence Types
Corymb - an inflorescence appearing to have a flat top;
indeterminate inflorescence with outer flowers opening first
Cyme - more or less flat topped, determinate inflorescence with
outer flowers opening last
Composite Head - a dense cluster of ray and disk flowers on a
very short axis
Umbel - indeterminate inflorescence ,usually but not necessarily
flat topped, with the pedicles and peduncles arising from a common
point; resembles the stays of an umbrella
Spike - unbranched, elongated, simple, indeterminate inflorescence
with sessile flowers
Spathe and Spadix - a thick, fleshy flower spike (spadix)
surrounded by a leaf or bract (spathe); ex: closet plant
Solitary - borne singly or alone
Panicle - indeterminate, branching inflorescence; the individual
branches are either raceme or corymbcorymb-like
Raceme - simple, indeterminate inflorescence with pedicelled
flowers
corymb
umbel
Composite
head
spike
Spathe &
spadix
solitary
panicle
raceme
cyme
www.pssc.ttu.edu/pss1411cd/STRUCTUR/inflores/inflores.ht
m
Categories Determined By Parts Present
Perfect - a flower that contains both pistillate
(female) and staminate (male) parts; may or
may not have petals or sepals
Complete - has all four parts of the flower
present: sepals, petals, pistil, and stamen
Staminate - having stamens and no pistils; a
male flower
Pistilate - having pistils and no stamens; a
female flower
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Fruit,, seedFruit
seed-bearing structure of a
flowering plant. A fruit is actually a
ripened ovary, a component of the
flower’s female reproductive structure
Fruits
Fleshy Fruits
Berry - fruit with the pericarp fleshy throughout and seeds inside
the fruit
Tomato
Specialized Berries
Hesperidium - a berry with leathery exocarp and mesocarp; the
endocarp is segmented and very juicy
Orange
Pepo - a berry with a hard and very thick exocarp or rind
Cantaloupe
Pome - a fleshy fruit produced by an
inferior ovary; the endocarp enclosing
many seeds is commonly called the core
Apple
Stone (or) Drupe - a fleshy fruit, usually
one seeded; the seed is enclosed in a
stony endocarp
Cherry
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Dry Dehiscent Fruits - dry fruits which split
along definite lines to release seeds at maturity
Legume - single celled, splits along two sutures
releasing the seeds
Silique - consists of two cells, splits along two
sutures releasing the seeds
Capsule - short and rounded fruit, consists of
more than one carpel
Dry NonNon-dehiscent
Fruits - dry fruits which
do not split along definite
lines to release seeds at
maturity
Acorn - single celled,
single seeded fruit of
oaks
Samaras - a dry, nonnondehiscent, winged fruit
Multiple fruits are actually bunches of
fruits growing together, and each fruit has
developed from its own flower. An
aggregate fruit derives from one flower
with several pistils, but a multiple fruit
develops when the pistils of several
distinct flowers mature and grow packed
together
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www.backyardnature.net
Plant Processes
There are 4 major
processes that plants
depend on for growth
and reproduction
1. photosynthesis
2. respiration
3. transpiration
4. sexual
reproduction
www.hcs.ohio--state.edu:
www.hcs.ohio
state.edu:
Photosynthesis
Photosynthesis is the
process by which light
energy is utilized to
convert carbon
dioxide and water into
food to be used by
plants. Oxygen is
released into the air
during the process.
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Light or solar energy is captured by
chlorophyll, the green pigment in leaves.
It is then converted into chemical energy
which is stored as starch or sugar.
They are available to the plant as food or
fuel.
Plants differ from animals in that animals
cannot manufacture their own food from
light energy. The word photosynthesis
means "to put together with light":
6CO2 + 6H2O + energy -> C6H12O6
(glucose) + 6O2
Because all plants need light to grow they
often compete for light. Shading of one
plant by another should generally be
avoided when planting.
Some plants
such as Hosta and ivy are shadeshade-adapted
and may even be injured by high light
conditions
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respiration
The food that a plant
stores is used by the
plant for new growth.
The process of
converting stored
food into usable
energy is called
respiration.
It is similar to burning
wood to release
stored energy as heat
and light. Just as fire
requires oxygen to
burn, respiration, or
the "breaking down"
of stored sugars,
requires oxygen to
release energy for
new growth.
Water and carbon
dioxide are released
during plant
respiration. This is the
same as in animal
respiration.
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Respiration is essentially the opposite of
photosynthesis. It uses food plus oxygen
to change chemical energy into heat and
an energy form usable by the plant. Light
is not needed in this process. An example
of a plant using stored food can be seen
when a potato sprouts in storage
C6H12O6 + 6O2 -> 6 CO2 + 6H2O +
energy
transpiration
Transpiration is a
necessary evil for
plants. As they open
their stomata to take
in carbon dioxide for
photosynthesis they
cannot help losing
water by evaporation.
.
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The loss of water through the stomata in
the leaf pulls water up through the plant
from the roots.
The stream of water
moving through the xylem also carries
nutrients from the roots to other parts of
the plant.
When additional water is unavailable to
the roots, as in winter or drought, wilting
and plant damage can occur.
reproduction
Seed formation begins when the pollen is moved
from the male part of the flower (the stamen) to
the female part (the pistil). Pollination is the
transport of pollen from the anther onto the
stigma. Pollen can be carried by insects, other
animals, or wind.
encarta.msn.com
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When pollen touches the stigma, a long
tube (the pollen tube) grows from the
pollen down through the style until it
reaches the ovary. Male sex cells travel
down the pollen tube and unite with
female sex cells in the ovary. This union of
a male and female cell is called
fertilization
Self-fertile plants may be pollinated with
Selfpollen from the same flower or other
flowers on the same plant. Most plants are
self--fertile
self
Some plants are selfself-sterile and cannot
be fertilized by their own pollen. Pears,
plums, and some apples are selfself-sterile.
They require the presence of another
variety of apple tree, a "pollinator" for
fertilization.
Fertilization results in
an embryo which
develops inside
protective layers of
tissue. The embryo
and protective layers
are called a seed.
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A seed consists of
three parts: a
Dormant Embryo,
Embryo, a
Storage Tissue,
Tissue, and
a Seed Coat.
Coat.
Germination “sprouting”
Some seeds sprout with just water and reasonably warm
temperatures. This is true of most common garden
plants. Such seeds are often referred to as "seeds
lacking dormancy."
Wild species usually have some kind of deeper
dormancy to avoid sprouting in late summer/fall when
the seeds are dispersed. This assures that tender
seedlings are not frozen at a young age, but do not
appear until warm weather arrives in springtime. For
these species it takes something more than just water
and warmth to germinate.
.
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Corn - a monocot
bean - a dicot
The mother plants of our "wild" species put their
embryos into dormancy by using chemicals. Perhaps in
hardy plants the vast majority use abscisic acid to keep
their embryos from germinating too early. This chemical
is broken down by enzymes in the embryo over time.
The enzymes have a cold temperature optimum. Thus
the enzymes are not active until early winter. The
abscisic acid keeps the embryo dormant from dispersal
to frost. After 6 weeks at about 4°
4° C, the optimum for
the enzymes that metabolize abscisic acid, the AbA is
metabolized completely. But now the cold soil keeps the
embryo dormant until the warmth of spring (20°
(20° C). It is
an ingenious mechanism evolved in hardy plants.
Seeds remain dormant or inactive until
conditions are right for germination. All
seeds need water, oxygen, and proper
temperature in order to germinate. Some
seeds require proper light also. Some
germinate better in full light while others
require darkness to germinate.
When a seed is exposed to the proper
conditions, water and oxygen are taken in
through the seed coat. The embryo's cells
start to enlarge. Then the seed coat breaks
open and a root or radicle emerges first,
followed by the shoot or plumule that
contains the leaves and stem
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