Download After the flower….

Plant Reproduction…
Fruits and Seeds
(Take notes on Underlined Information)
We already looked at the flower
Pollen (plant sperm)
Pollen Dispersal
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Animals
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usually barbed or
sticky
Bees, Flies, etc
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Mammals
Birds
Wind
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80% of pollination
usually light &
aerodynamic
Water
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for plants that grow
underwater
eg. Eelgrass
Pollination (Fertilization)
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Pollen sticks to the sticky
substance on the stigma
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The sperm break out and
create a pollen tube
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Every fruit requires two
sperm – one to fertilize
the embryo and one to
fertilize the endosperm
(food for the embryo)
Pollen Tube Formation
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Pollen swells from
moisture on stigma
Pollen tube grows so that
sperm can reach the egg
200-300 nm/second
growth
Fastest growing cell type
known
(Yellow pollen in picture
is a different species that
won’t be allowed to reach
the egg cells.)
What is a Seed?
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A seed is the reproductive unit of a
flowering plant. From a reproductive point
of view, a seed has the “baby” plant inside.
Seed Dispersal
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Dispersal: Species
movement away from an
existing population or away
from the parent organism
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Animal dispersal
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Most birds lack sensitive
noses and are much more
reliant on color when
finding food – red, hot pink,
orange.
Insects can have excellent
senses of smell or color
vision or both – especially
like blues, yellows and
purples.
Some fruits contain a
laxative that ensures that
the seed will be released
from the digestive tract
fairly quickly.
Seed Dispersal…
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Wind
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Usually light (low
density) & aerodynamic
May have wings
Sycamore Seed
Water
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For plants that grow in or
near large bodies of
water (eg. Coconut)
Density less than that of
water so they can float
Must be somewhat
waterproof
Wood Hawthorne Seed
Surf grass Seed
What is a Fruit?
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Fruit is the enlarged ovary and any other
floral part that undergoes a post-pollination
development
Fruits are what is left of the flower after
pollination
What is a Nut?
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A nut is a hard fruit
with a seed inside.
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The nutshell,
technically, is the fruit.
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The part we eat is the
seed.
So many examples…
Each lab station contains pictures and
detailed information on various seeds,
fruits and nuts.
(Spend about 2-3 minutes at each station)
Coconut
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Some scientists like to refer
to the coconut as a water
dispersal fruit and seed.
If you look at one end of the
coconut, you’ll see three
pores.
The coconut seed
germinates and a shoot
emerges from one of the
pores.
In addition to the “baby”
plant in the seed, there is
the food to kick off its life
called the endosperm.
The endosperm is what
makes up most of the seed
and, in the coconut’s case,
is the yummy white stuff we
eat.
Flower
Pomegranate
(Leathery Berry)
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The name pomegranate
derives form Middle
French, pomme garnete,
literally "seeded apple”
Pomegranates contain
840 arils “seeds” that are
compartmentalized.
As the flower dries up,
the base of the flower
(now fertilized) swells into
the berry we know.
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Look closely at the end you can
see the dried up stamen
Buckeye (Capsule)
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Hummingbirds
pollinate this tree.
Flowers are
poisonous to honey
bees!
The seeds are
poisonous to
humans when raw.
Coast Live Oak
(Nut)
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The chances of one
acorn making it to
become an oak tree
are very slim -- less
than 1/10,000
Acorns are eaten by
squirrels, birds, deer
and woodpeckers.
Birch (Catkin)
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Fruit is called a winged
nutlet.
Used by native
Americans to make
canoes and other tools.
Birds, rabbits and
rodents feed on the
bark and seeds.
Flower
Immature Catkin
Mature Catkin
Magnolia
(Aggregate Follicle)
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Aggregate fruit that is
woody.
Not a cone like pine.
They are typically
pollinated by beetles.
They don’t produce any
nectar that bees and birds
would like but the beetles
eat the pollen which is
high in protein.
Most primitive flowering
tree.
Carob (Pod)
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Carob pods are
processed to a
cocoa -like flour and
are sometimes used
as a chocolate
substitute
Significant odor (go
ahead, smell them)
Liquidambar (Capsule)
aka Sweetgum
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Female flowers, after
pollination, develop into the
spikey balls you have
probably all seen.
After they dry out and turn
brown, the mature seeds
are released.
The Sweetgum received its
name because the cut bark
releases a sweet, fragrant
liquid used in some
perfumes
Male
Flowers
(above)
Female
Flowers
(below)
Female
Flowers
Pine (Conifer)
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Native Americans used
pine tree sap as a way
to stop bleeding.
Pine cones are what’s
left after the female
flower has been
pollinated.
Squirrels love to eat
them.
Male
Flowers
Artichoke (Achene)
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The part of the
artichoke that we eat
(heart), is a vegetable.
We eat them before the
flowers mature.
Typically, the insides or
choke (ovaries and
eggs), are scooped out
and we eat the fleshy
support (heart).
It’s in the same family
as thistles and the
sunflower.
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Pineapple (Multiple Fruit of
Berries)
Growers don’t
actually want flowers
to be pollinated since
this would produce
seeds.
They make “new”
pineapples by twisting
off the top stalk and
replanting it
(vegetative
reporduction!)
Flowers
Grass (Grain)
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Grass plants are 70 to 80%
water and clippings are 90%
water
The front lawns of 8 average
houses have the same cooling
effect as 24 (3-4 ton capacity)
home central air conditioning
units
A 50 by 50 foot grass lawn
(2,500 square feet) releases
enough oxygen for a family of
four, while absorbing carbon
dioxide and other toxins.
Dandelion
(Achene - Composite)
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The Dandelion provides an
important food source to bees.
The pollen from this plant helps
bees out in the spring because it
flowers early and the flowers
continue through to the fall
providing constant food.
93 different kinds of insects use
Dandelion pollen as food.
This plant has been used for over
1000 years for medicinal
purposes.
Apple (Pome)
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Apples are not grown from seed,
they are either propagated by
grafting or budding (asexual).
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Apples are a member of the rose
family
It takes the energy from 50
leaves to produce one apple.
Apples are the second most
valuable fruit grown in the United
States. Oranges are first.
Orange (Hesperidium)
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Navel oranges are named
that because of the bellybutton formation opposite
the stem end. The bigger
the navel in an orange, the
sweeter it will be.
After chocolate and
vanilla, orange is the
world's favorite flavor.
Christopher Columbus
brought the first orange
seeds and seedlings to the
New World on his second
voyage in 1493.
Dogwood (Drupe)
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Bark of flowering dogwood was
used to treat mange, which may
explain the origin of the name.
Extracts and teas from different
species were used as a muscle
rub, to promote sweating to break a
fever, and to treat malaria.
Dogwood was used to treat
insomnia.
It was also used for whooping
cough and asthma.
Dogwood was an early toothache
treatment and it was a
"toothbrush."
The bark, twigs, flowers, berries,
leaves and roots are all usable.
Corn (Grain)
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An ear of corn averages
800 kernels in 16 rows.
Every piece of corn silk is
actually the leftover style
and leads to an individual
ovary (eventual kernel)
Each year, a single U.S.
farmer provides food and
fiber for 129 people - 97
in the U.S. and 32
overseas.
Male
Flowers
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Female
Flowers
Maple (Samara)
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It takes 30-50 gallons of sap to
make one gallon of maple syrup
Tapping does no permanent
damage to the tree and only 10
percent of the sap is collected
each year.
Many maple trees have been
tapped for 150 or more years.
The flowers are pollinated by
bees.
Birds, squirrels, and other
rodents usually consume only a
negligible amount of the seeds.
Tomato (Berry)
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The botanical family of tomatoes is
the same nightshade family as
tobacco, potatoes, aubergine
(eggplants), chilli peppers, and the
poisonous belladonna.
While the fruit is perfectly safe and
healthy to eat, the plant's leaves
are actually toxic.
Berry: simple, fleshy fruit that
usually has many seeds (e.g., the
banana, tomato, or cranberry). The
middle and inner layers of the fruit
wall often are not distinct from each
other
Pumpkin (Pepo)
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Pumpkins contain
potassium and Vitamin A.
Pumpkin flowers are
edible.
In early colonial times,
pumpkins were used as an
ingredient for the crust of
pies, not the filling.
The largest pumpkin ever
grown weighed 1,140
pounds.
Pumpkins are 90 percent
water.
Female
Flower
Male
Flower
Redwood (Conifer)
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One tree can weigh 1.6
million pounds
Can live up to 2000
years!
Can reproduce through
seeds or by shoots.
(sexual or asexual)
Redwood trees use their
needles to condense fog
and let it drip down on
their own roots!
Female Flowers
appear only on the tips of
the uppermost branches
Sunflower
(Achene)
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Sunflower heads consist
of 1,000 to 2,000
individual flowers joined
together by a receptacle
base.
The large petals around
the edge of a sunflower
head are individual ray
flowers which do not
develop into seed.
A well-known sunflower
characteristic is that the
flowering heads track the
sun's movement, a
phenomenon known as
heliotropism.
Agapanthus (Capsule)
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The pollen is blue.
Bees pollinate the flower.
The perennial Agapantus grow from an
underground rhizome each year (asexual)
Agapanthus is suspected of causing
haemolytic poisoning (ruptures red blood
cells) in humans, and the sap causes severe
ulceration of the mouth.
Agapanthus contains several chemicals that
have anti-inflammatory (reduce swelling and
inflammation), anti-oedema (oedema swelling due to accumulation of fluid),
antitussive (relieve or suppress coughing)
and immunoregulatory (have influence on the
immune system) properties.
Olive (Drupe)
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The color of the olives depends on
when they were harvested. Green
ones are less ripe, black are more
ripe.
Olives straight from the tree don’t
taste right until they’ve been cured in
a salty solution.
No olive trees come from seeds, all
are from cuttings of a “parent” tree
(actually a clone!)
The olive produces two kinds of
flowers: a perfect flower containing
both male and female parts, and a
staminate flower with stamens only.
Chinquapin
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In the chestnut family edible