Plants

All Photos and Text by Kris H. Light Copyright 2009

Kingdom - Plantae

What good are plants? ²Plants are used as:

U Food sources for people and animals U Building materials – wood, bamboo U Herbs and Spices U Coffee, Tea, Chocolate , cola drinks U Clothing (cotton, linen, hemp) U Source of some medicines (morphine, digitalis, quinine) U Homes for animals U Erosion prevention U Paper, cardboard, paper towels U Add beauty to the world U Make Oxygen

Plant Cells UPlant cells are different than animal cells, they have a cell wall which contains cellulose. They also have chloroplasts for photosynthesis. Chloroplasts

Cell wall

Nucleus

A typical plant cell

Leaves U The purpose of leaves is to produce food (sugar) for the plant by way of photosynthesis. Different parts of the leaf have different jobs. The veins in a leaf carry water and minerals and return food (sap) from the leaf to the roots and the rest of the plant. Veins also help to support the leaf.

Photosynthesis Photosynthesis means “put together with light”. The process takes place in the leaves. Six molecules of water plus six molecules of carbon dioxide, in the presence of sunlight and chlorophyll, produce one molecule of sugar (glucose) plus six molecules of oxygen.

Water + Carbon dioxide

=

Glucose + Oxygen

Sugar

Cross-section of a Leaf Waxy Cuticle protects leaf

Phloem (moves sap down to roots)

Xylem

(moves water up from roots to leaves)

Upper epidermis Palisade layer cells (photosynthesis) Spongy layer cells (gas exchange) Vein

Lower epidermis Stomata (Guard cells – allow transfer of Oxygen and carbon dioxide)

Vein Patterns UVein patterns are one way to help identify trees. UPinnate = “featherlike” UPalmate = “like fingers” Pinnate

Palmate

Leaf Placement

Opposite Whorled

Alternate

Basal

U Leaves are not just stuck on a plant, they grow in a way to get as much light as possible. U Opposite U Alternate U Basal U Whorled U Rosettes

Fall Leaves

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Leaves turn color in the fall because they lose their chlorophyll and the red and green pigments begin to show through.

Flowers

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UThe purpose of flowers is to make seeds. Flowers have different parts for different “jobs”. UFlowers appeared during the Cretaceous Period (late dinosaur time) about 125 million years ago.

Anthers and Pistils UAnthers are the male

Anthers Pistil

parts of the flower. They make pollen. UPistils are the female parts of the flower. Pollen is deposited there.The ovary, where the seeds form, is located at the base of the pistil.

Parts of Flowers – Sepals and Petals USepal – Bud cover,

holds up petals; usually green, sometimes same color as petals. UPetals – “Advertisement” and landing place for pollinators; nectar guides lead pollinators to nectar at base of petals

Nectar guides

Petals

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Nectar Guides – “Floral Road Maps”

U Some flowers have “nectar guides” to show the insects where to find food (nectar). They can be spots, lines, or bright colors.

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Pollinators ×Pollinators are animals that spread pollen from one flower to another. They can be insects, birds, bats. ×The wind is a pollinator for some kinds of flowers.

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Some Insect Pollinators

Bumblebees

Flies

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Moths

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Butterflies

Other Pollinators

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Wasps

Bats

Birds

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Wind Ants

Beetles

Stinky Flowers Attract Flies and Beetles USome flowers smell REALLY bad! These flowers attract flies and beetles as their pollinators. Most of them have a maroon color on the flower petals to look like dead meat.

Wind-pollinated Flowers U Grass flowers do not have petals because they do not have to attract pollinators. U The anthers are the yellow and brown structures hanging down from the plant. The pistils are the fuzzy white structures. U Corn is the female flower. The silks are the pistils and the grains are the fertilized seeds.

Seeds Cotyledon – stored food Embryo

Root Seed Coat Cotyledon

U Seeds are the way most plants reproduce. The seed coat protects the seed from disease and drying out. When a seed receives water, it can germinate. The stored food swells, the embryo begins to grow and the root emerges from the seed. The embryo is the baby plant, complete with small leaves. The cotyledon is the stored food, it often stays on the plant until the plant is able to grow on its’ own. Sprout

Seed Dispersion U Seeds are spread by: U Animals – defecation, burying, or hooks U Wind – wings or parachutes U “Mechanical” (thrown) U Water

Seeds we eat U When we eat seeds we use the stored food as food for ourselves. You can often taste the sugar. The embryo (baby plant) is also used as food. U Some seeds are small, some are very large. U We get oils, starches and sugars from seeds.

Cotton is a fruit, it has seeds!

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Cotton Flower

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Cotton Bolls (fruit)

Roots URoots have 3 purposes: U1. Holds plant in the soil U2. Takes up water U3. Stores food for the plant

Taproot

Diffuse roots

Aerial roots

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UCypress trees live in water-filled swamps. Tree roots must have oxygen. The cypress trees get oxygen through the aerial roots that grow upward out of the wet ground .

Plant Adaptations UPlants have many different and

interesting ways of surviving their habitats: UThorns, spines UStored water in leaves (succulents) ULose leaves in winter UHairy leaves UPoisons

Desert Plants Many Desert plants have spines, thick skin, and they store water in the stems.

Flowering Plants that are not Green U These Indian Pipes are flowering plants that do not have chlorophyll. They do not have leaves. Since they can’t make their own food they break down dead leaves in the soil. They are called “saprophytes”. Indian Pipes

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Parasitic Plants

Squawroot

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Dodder – the “Vampire Vine”

Some plants are not able to make their own food through photosynthesis. They must “steal” food From other plants. They are called “parasites”. There are about 4000 different kinds of parasitic plants throughout world.

Carnivorous Plants Round-leaf Sundew

U Carnivorous plants live in water or poor soil without many nutrients. They have to get their minerals from insects or microscopic aquatic animals. Some have sticky tentacles or greasy leaves that catch insects; others have small bladders that catch animals in the water.

Butterwort

Pitcher Plant

Thread-leaf Sundew

Venus Fly-trap – a carnivorous plant

Trigger hairs

Venus Fly-trap plants grow wild in the bogs of eastern North Carolina. They are often grown in laboratories and sold in stores. The plants capture flies and other insects to suppliment their need for nitrogen. If a fly hits two of the three trigger hairs on a leaf pad, the leaf closes and captures the insect. It is digested by chemicals in the leaf.

Poisonous Plants – Poison Ivy U “Leaves of 3, let them be!” U It is important to learn what poison ivy looks like. It has 3 leaflets with a long middle stem. The vine has hairy holding roots. The berries are white in the winter. U Wash the exposed area with soap as soon as possible.

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Berries

Trees UTrees come in many shapes, sizes, and colors. They can be identified by their Palm – not a leaves, bark, twigs, real tree and shape.

Tree Bark Hackberry

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Sycamore

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Sourwood

UTrees have different kinds of bark. It is an easy way to identify some kinds of trees. USome types of bark are: smooth, rough, furrowed, scaly

Kinds of wood in a tree Heartwood – this part is the center of the tree trunk. It fills with old sap and no longer carries water. It is stronger than the other wood. Xylem – the part of the Trunk that carries water From the roots to the Rest of the tree.

Cambium – produces new cells to make wood (makes tree rings)

Outer bark – protects the tree from insects, disease, and from drying out Phloem – the part that takes the food (“sugar”) from the leaves to be stored in the roots.

Tree rings

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U Trees are different from other plants, they do not die back in the winter. Each year they add a new layer of growth. Trees have growth rings in the wood. If you count the rings, you can tell how old the tree was when it was cut down.

U Twigs are the ends of the tree branches. New growth takes place at the ends of the twigs. Can you see the growth rings on the twig on the bottom picture? U The new leaves are protected by the scales on the leaf buds. Can you see the leaf buds on these twigs?

Twigs Terminal bud

Twig growth rings

Flowering vs. Non-flowering Plants UFlowering: UMost reproduce by making seeds. USome are wind pollinated, others animal pollinated.

UNon-flowering: UMosses UFerns ULiverworts UMost reproduce by making spores. They do not make seeds. UMany live in damp areas.

Ferns and Mosses Moss

Liverwort Fern

UFerns and mosses were around long before plants with flowers, before the time of the dinosaurs. Coal is made from these decomposed prehistoric plants.

Moss UMosses grow in damp areas in the woods, on rocks, on trees.

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Moss and Lichen

Fungi U Fungi decompose dead plants and turn them into soil; they are “nature’s recyclers”. These shelf fungi grew on the tree early in the stages of decomposition. Different types of fungi attack the wood at different stages.

Mushrooms

Stalked Puffball- in-aspic

Columned Stinkhorn with flies (they spread the spores!)

U Mushrooms, puffballs and stinkhorns are not plants, they are in the kingdom Fungi. These organisms reproduce by making microscopic spores.They do not have chlorophyll and they are not green. Many mushrooms are poisonous.

Lichens

Crustose lichen

Christmas Lichen

Foliose lichen

U Lichens are not plants. They are in the fungus and protista kingdoms. They have both fungal and algal cells. The fungus gives the organism shape and holds water; the algae produce food for the organism through photosynthesis. U There are 3 different kinds of lichens: Crustose Foliose Pixie Cups Fruticose

British Soldier Lichen

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Structure of British Soldier Lichen Reproductive bodies Algal cell

Fungal strand

Algae UAlgae (seaweed, “pond scum”) are not plants either. They belong to the kingdom Protista. USome are microscopic, onecelled; some are huge ocean kelp.