The Story of Flowering Plants: flowers, fruits and seeds and seedlings. Matthaei Botanical Gardens and Nichols Arboretum, University of Michigan

Transcription

1 The Story of Flowering Plants: flowers, fruits and seeds and seedlings Matthaei Botanical Gardens and Nichols Arboretum, University of Michigan

2 And now; SEEDS and PLANT PARTS for 2 nd & 3 rd graders! When flowers are pollinated & fertilized they make seeds. kidsgrowingstrong.org

3 Flowers have 5 major parts: Petal, Sepal, Stamen, Pistil, & Stem May also be called a carpel

4 Matthaei Botanical Gardens and Nichols Arboretum, University of Michigan

5 Pollination: Fertilization: Pollination and Fertilization Make Seeds Pollen moves from the anthers to the stigma. 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. Ovary Fruits arise from a ripened 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.

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7 Flower parts and their roles See the seeds developing in the flower ovary?

8 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

9 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

10 Tree flowers may be wind or insect pollinated Tube shaped flowers are usually pollinated by butterflies, moths or hummingbirds.

11 Examples of pollinators and preferred flowers Matthaei Botanical Gardens and Nichols Arboretum, University of Michigan

12 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).

13 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 Matthaei Botanical Gardens and Nichols Arboretum, University of Michigan

14 Now that we understand pollination of flowers, let s look at seeds!

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

16 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 Matthaei Botanical Gardens and Nichols Arboretum, University of Michigan Exocarp: Exo means out. This outer layer holds the fruit together. It forms the skin of a grape or peach.

17 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.

18 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

19 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

20 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?

21 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.

22 Plants usually have two types of roots 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.

23 As the seed grows, it develops a shoot. Shoots grow above ground and become stems & buds. A stem can be hard and woody or soft and herbaceous.

24 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?

25 Some stems grow under or along the ground. These are called r hizomes and are special underground stems. Ginger is a kind of rhizome.

26 Leaves are an important plant part. A leaf s job is to 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.

27 Some evergreen leaves are flat and broad. These evergreens prefer to live in warm climates, or have waxy coverings to keep them from drying out in the winter. But their main job to capture sunlight. Rhododendron Banana Boxwood Bromeliad

28 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