the story of plants flowers to seeds & back again! · pdf filematthaei botanical gardens...

The Stor y of P lants F lowers to Seeds & Back A gain!

Matthaei Botanical Gardens and Nichols Arboretum, University of Michigan


kidsgrowingstrong.org

Let’s start with pollination!

Flowering plants produce flowers that when pollinated & fertilized make seeds.

F lo w e r s h a v e 5 m a j o r p a r t s : p e t a l, s e p a l, s t a m e n , p i s t i l , & s t e m


Matthaei Botanical Gardens and Nichols Arboretum, University of Michigan http://www.bb.iastate.edu/necgex/Flowers.htm

Petals direct the pollinator to the flower. Sepals hold the petals.

Stamens have anthers and filaments. Filaments hold the pollen.

Pistils have a stigma, style and ovary. Fruits arise from a ripened ovary.

Stems hold the flower upright, carry nutrients and hold the developing fruit on the plant.

http://online.morainevalley.edu/WebSupported/BIO112/plants_and_ecology_notes.htm

Pollination: Pollen moves from anthers to stigmas.

Fertilization: Pollen lands on the stigma, pollen tube develops and fertilizes

the ovary at the base of the flower


Seeds develop as the result of pollination & fertilization

Flowers come in many shapes and

sizes, to attract different

pollinators.

Who might pollinate these

flowers?



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


Tube shaped flowers are usually pollinated by butterflies, moths or hummingbirds.

Male red maple flower Female red maple flower

Tree flowers may be wind or insect pollinated

Male red oak flowers w/ new leaves


http://evolution.berkeley.edu/evolibrary/home.php

First a flower, then a fruit and inside the fruit are seeds!

http://www.botany.org/bsa/misc/mcintosh/mcinto20.html


Seeds contain all the material necessary to grow into a new plant

Seed parts have special names and special jobs to do: Coat, Endosperm, Embryo



PERICARP: The part of a fruit that surrounds the seed. The pericarp consists of the endocarp, mesocarp, and exocarp. ENDOCARP: The pericarp layer surrounding the seed. MESOCARP: The middle layer, usually fleshy. EXOCARP: The outer pericarp layer. It forms the skin of a grape or peach.

Taken from MSU extension service http://www.extension.org/pages/55717/exocarp

Seeds can be found inside fruits or covered with a thin shell, like an acorn or a sunflower seed. Peaches are fleshy fruits with seeds covered by a hard case called an endocarp.

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.

Why is it called a fruit?


Flowering plants may be monocots or dicots. 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 stores energy for the growing plant,

and develop a single first leaf within a sheath. Dicots, like beans, have 2 cotyledons for the growing plant and develop 2 first leaves.

biology.unm.edu

Here are examples of a growing dicot (beans), and a growing monocot (corn). Notice that the dicot bean has 2 cotyledons and the monocot, corn has 1 cotyledon covered by a sheath.

S e e d g e r m i n a t i o n , b e a n s v s . c o r n B e a n s a r e d i c o t s a n d h a v e 2 f i r s t l e a v e s .

C o r n i s a m o n o c o t a n d h a s 1 f i r s t l e a f .


N e w p la n t s m a y h a v e t w o g e n e r a l t y p e s o f r o o t s

Dandelions are dicots with tap roots. These grow from the seed part called the embryo radicle. Tap roots grows deep into the soil.

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.


A s t h e p l a n t d e v e l o p s , i t g r o w s a s h o o t . S h o o t s a r e a b o v e g r o u n d a n d i n c l u d e s t e m s &

b u d s


R h i z o m e s a r e s p e c i a l u n d e r g r o u n d s t e m s . G i n g e r i s a k i n d o f r h i z o m e .


L e a v e s c a n b e d e c i d u o u s o r e v e r g r e e n . A l e a f ’s j o b i s t o c o l l e c t s u n l i g h t .

From top to bottom:2- and 3-needle pines, spruce, fir, Douglas fir, cedar, larch. Matthaei Botanical Gardens and Nichols

Arboretum, University of Michigan

S o m e e v e r g r e e n l e a v e s a r e f l a t a n d b r o a d . B r o a d l e a f e v e r g r e e n s l i v e i n w a r m c l i m a t e s .

Rhododendron

Boxwood Bromeliad

Banana


And back to new seedlings where we start all over again!


the story of plants flowers to seeds & back again! · pdf filematthaei botanical gardens...

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