The Story of Flowering Plants: flowers, fruits
and seeds and seedlings
Matthaei Botanical Gardens and Nichols
Arboretum, University of Michigan
And now; SEEDS and PLANT PARTS for 2nd & 3rd graders !
When flowers are pollinated & fertilized they make seeds.
kidsgrowingstrong.org
F lowers have 5 major parts:
Pe t a l , S e p a l , S t a m e n , P i s t i l , & S t e m
May also be
called a carpel
Matthaei Botanical Gardens and Nichols
Arboretum, University of Michigan
Pollination and Fertilization
Make Seeds
Pollination:
Pollen moves from the anthers to the stigma.
Fertilization:
Pollen lands on the stigma, a pollen tube develops
and fertilizes the ovary at the base of the flower
Seeds:
The result of pollination and fertilization. Also called ovules found in
the ovary.
Flower power! Important to pollination:
Petals Attracts the pollinator to the flower.
Sepals
Hold the petals and also cover the young developing bud before the flower blooms.
Stamens Male part of the flower, composed of anthers and filaments.
Pollen
Is found on the filament
Pistil (also called a carpel) has a stigma, style and ovary. It is the female part of a flower.
Fruits arise from a ripened ovary.
Ovary holds ovules which will become seeds. A fertilized ovary changes into a fruit.
Stems
hold the flower upright, carry nutrients and hold the developing fruit on the
plant.
Flower parts and their roles
See the seeds
developing in
the flower
ovary?
http://www.bb.iastate.edu/necgex/Flowers.htm
Flowers come in
many shapes and
sizes, to attract
different
pollinators.
Guess who
might pollinate
these flowers?
Matthaei Botanical Gardens and Nichols
Arboretum, University of Michigan
Flowers with flat faces
are often pollinated by bees.
The flat petals make a good
perch for the bee while it drinks
nectar.
Flowers that are white & fragrant at
night may be pollinated by bats or
moths
Matthaei Botanical Gardens and Nichols Arboretum, University
of Michigan
Tube shaped flowers are
usually pollinated by
butterflies, moths or
hummingbirds.
Tree flowers may be wind
or insect pollinated
Examples of pollinators and preferred flowers
Matthaei Botanical Gardens and Nichols
Arboretum, University of Michigan
Flowers may produce different types of fruits & seeds
Simple fruit. A simple fruit
develops from a single
carpel (or several fused
carpels) of one flower
(examples: lemon, peanut,
banana).
Aggregate fruit. An
aggregate fruit
develops from
many separate
carpels of one
flower (examples:
raspberry, blackberry,
strawberry).
Multiple fruit. A
multiple fruit develops
from carpels of many
flowers (examples:
pineapple, mulberry,
osage-orange).
Accessory fruit. An
accessory fruit contains
other floral parts (such as
the receptacle) in addition
to ovaries ( examples: apple,
strawberry).
Flowers may be pollinated by more than one thing: wind, bird,
or insect.
But most pollinators prefer a specific type of flower,
and most flowers have a best way to be pollinated
http://evolution.berkeley.edu/evolibrary/home.php
Matthaei Botanical Gardens and Nichols
Arboretum, University of Michigan
Now that we understand pollination of flowers,
let’s look at seeds!
Remember: First a flower, then a fruit and inside the
fruit are seeds!
http://www.botany.org/bsa/misc/mcintosh/mcinto20.html
So, what’s a fruit?
Fruits have seeds inside. They might be fleshy, like a peach or dry, like a nut. They develop
from a fertilized flower. The ovary wall swells and creates layers surrounding the seed.
Fruits have a pericarp that surrounds the seed..
Pericarp: ‘Peri-’ means around, the
pericarp is made of the endocarp,
mesocarp, and exocarp. The pericarp
surrounds the seed.
Endocarp: ‘Endo’ means inside. This thin
layer surrounds and protects the seed.
Mesocarp: ‘Meso’ means middle. This
middle layer, is between the exocarp and
the endocarp.
Image from MSU extension service
http://www.extension.org/pages/55717/exocarp
Exocarp: ‘Exo’ means out. This outer layer
holds the fruit together. It forms the skin
of a grape or peach.
Matthaei Botanical Gardens and Nichols
Arboretum, University of Michigan
How many different fruits ?
Fruits come in many
different forms,
and there are many
different names for these
fruits.
But all fruits come from
flowers & all fruits have
seeds.
The fruit comes from the
ovary wall. The seeds are
the fertilized ovules.
Let’s look inside the fruit to find the Seeds!
NATURE’S NEW PLANT PACKAGE
Seeds have everything the plant needs to make a new plant.
Most seeds have a seed coat, endosperm and embryo and a cotyledon.
Seed coats protect the seed.
Endosperm stores nutrients.
The embryo is the baby plant.
The cotyledon is part of the developing seed.
When the seed takes on water and germinates, the cotyledons swell, a root radicle emerges
and a shoot develops.
Scientist divide plants into monocots or dicots based on number of cotyledons.
Monocotyledons have one first leaf and one cotyledon. Also called a monocot.
Dicotyledons have two first leaves and two cotyledons. Also called a dicot.
Corn is an example of a monocot.
Beans are an example of a dicot.
Matthaei Botanical Gardens and Nichols
Arboretum, University of Michigan
Corn-a monocot and Beans-a dicot.
Both monocot and dicot seeds have endosperm; stored energy for the developing plant
which is surrounded by the seed coat.
Monocots, like corn, have 1 cotyledon, which also stores some energy for the growing
plant, and develops a single first leaf within a sheath.
Dicots, like beans, have 2 cotyledons for the growing plant and develops 2 first leaves.
In both cases, when the leaves grow above ground they can start photosynthesis. Plants
make food through photosynthesis.
biology.unm.edu
Let’s go back to monocot and dicot seeds for a quick review.
What is the name of the food
storage part of a seed?
What part sprouts from the
growing seed first? Root or shoot?
Corn is a monocot, beans are
dicots. How many first leaves will
a corn seedling have?
How many first leaves will a bean
sprout have?
What part of the flower does the
seed come from?
You’re almost a plant expert!
Let’s move to other important parts of a plant.
Roots: tap roots and fibrous roots anchor plants
and absorb minerals and water.
Stems: shoots hold the plant upright, and
conduct water and nutrients up and down the
plant.
Leaves: come in many shapes and sizes and
make food for the plant through
photosynthesis.
P la n t s u s u a l l y h a v e t w o t y p e s o f r o o t s
Dandelions are dicots with tap roots.
Remember the root radicle part of the
seed? This grows into more roots. Tap
roots grows deep into the soil to anchor
the plant and absorb water.
Grasses are monocots with fibrous roots
at the base of the stem. These do not
have a single large root, but have many
small roots. Fibrous roots spread out to
capture water near the surface of the soil.
As the seed g rows, it develops a shoot.
Shoots g row above g round and become stems
& buds. A stem can be hard and woody or soft
and herbaceous.
Stems hold plant upright to reach the sun.
Stems may have buds. Buds may contain baby
leaves, some buds contain baby flowers.
This picture shows a tomato plant from
root tip to shoot tip. Look for all the
parts of the plant. Can you find them all?
Some stems grow under or along the
ground. T hese are called rhizomes and are
special underground stems. Ginger is a kind
of rhizome.
L e a v e s a r e a n i m p o r t a n t p l a n t p a r t . A l e a f ’s j o b i s t o
collect sunlight. They can be deciduous or evergreen.
Here are pictures of leaves found in Michigan.
From top to bottom: pines, spruce,
fir, Douglas fir, cedar, larch.
Some evergreen leaves are flat and broad. These
evergreens prefer to live in warm climates, or have
waxy coverings to keep them from dr ying out in the
w i n t e r. B u t t h e i r m a i n j o b t o c a p t u r e s u n l i g h t .
Rhododendron
Boxwood
Banana
Bromeliad
Now that you now are a plant
expert, let’s explore seeds, fruits
and twigs up close!
Matthaei Botanical Gardens and Nichols
Arboretum, University of Michigan