Flowering trees



 



Some trees have two kinds of flowers on them – male flowers and female flowers. These catkins are male flowers. They are covered with pollen. The same tree also has small female flowers.



 



 





 



 



 



A holly tree can be male or female.



Holly trees or bushes are either all male or all female. Both male and female holly trees have white flowers. Berries only form on the female trees. To make new plants, there must be a male and female holly tree growing near each other. Insects carry pollen from the male to the female tree.



 



 





 



 



 



Both male and female flowers grow on a pine tree.



The male flowers are usually red or purple and the female flowers are often yellow or white. The female flower will become a pine cone if it is fertilized.



 



 



 



 





 



 



Most trees and bushes have flowers.



Some trees have flowers to attract insects, while others use the wind to spread pollen. Trees that use the wind usually have green, feathery flowers that hang from the tree.


Flower needs birds



 



Some flowers need birds to help them make seeds. Just like insects, some birds go to brightly coloured flowers in search of nectar. The pollen rubs off onto their beaks and feathers. They carry the pollen to other flowers.



 



 





 



Colourful flowers attract birds.



Birds are heavier than insects and a bird’s beak is hard. Because of this, bird-pollinated flowers are firm and tough. Birds have a poor sense of smell so these flowers don’t need to have a strong scent. Unlike bees, birds are not sensitive to ultra-violet light so flowers must be brightly coloured to attract them.



 



 





 



 



 



Humming-birds drink nectar from some flowers.



Some flowers need humming-birds to carry pollen to help them make seeds. Humming-birds also need flowers. They need the sugary nectar in these flowers for energy so that they can beat their wings up to 80 times a second!



 



 





 



 



Some bats and small animals like to drink nectar.



This tiny honey possum has a long snout and tongue for lapping up nectar from eucalyptus flowers. Its tongue can extend two centimeters from its body even though honey possums are only half the size of a mouse. Pollen rubs off onto the possum’s snout and is carried from one flower to another in this way.


Flowers Colour and scent



 



 



Some flowers have brightly coloured petals. When bees and other insects see these bright colours they go to the flower to search for nectar. Other flowers have strong scents so that insects will go to them.



 



 



 



 





 



This bee saw the petals and is looking for nectar.



Insects see differently from humans. Some colours that look dull to us can attract insects to flowers when they are searching for nectar. Some rare flowers are very brightly coloured and have unusual shapes to attract insects who might otherwise ignore them.



 



 



 





 



 



Some flowers have strong scents to bring insects to them.



The Buddleia bush smells so sweet and attracts so many butterflies that it is called the ‘butterfly bush’. It is the nectar in the flower that smells sweet. Some flowers, such as the Rafflesia, smell of rotting meat, which attracts flies to them.



 



 





 



An evening primrose looks different to a bee than it does to us.



Bees can see ultra-violet light so they can see flower markings that are invisible to us. The flower markings point towards the nectar, stamens and carpels in the middle of the flower. Some flowers, such as this evening primrose, even advertise a landing platform for bees. This way, plants make sure that plenty of insects visit them.



 


Making seeds



 



 



To make a seed, pollen has to go from the male part of one flower to the female part of another flower. Many flowers have help from insects to move the pollen. Some plants use the wind, birds and other animals to carry pollen.



 



 



 





 



 



 



If a bee goes into this flower, pollen may rub off onto its legs.



When an insect enters a flower, it rubs against the male stamens as it tries to find nectar to feed on. Sticky pollen attaches itself to the insect’s back and legs. The insect then flies to another flower. Some insects are furry to make sure that even more pollen sticks to them.



 





 



 



 



The bee carries the pollen to the next flower.



Pollination is when a pollen grain lands on the carpel of a flower. Plants that use the wind to transfer pollen must produce thousands of pollen grains. This way, at least some of them reach a carpel.



 



 





 



 



 



Pollen joins with an egg to make a seed.



When a pollen grain lands on the sticky carpel, it grows a tube down towards   the female egg. When they join they begin to produce a seed and seed’s casing. This process is called fertilization.



 


The parts of a flower

Flowers open out from buds in spring or summer when it is warm and light. Sepals on the buds keep them warm and dry until it is time to open. Sepals are usually green and look like small leaves.



A seed may grow inside the carpel.



Below is a cross-section of a flower and its stem. It shows the parts of flower. A group of carpels is called a pistil. Seeds may eventually form from the egg inside each carpel. Not all flowers have both the male and female parts.



 



 





 



 



 



The petals are orange and the sepals are green.



Most flowers are made of four parts – sepals, petals, carpels and stamens. The sepals protect the flower bud. After the bud has opened, the sepals have done their job and may fall off. Petals are often brightly coloured. They surround and protect the carpel and stamens inside them. There is sugary nectar in the base of most flowers.



 



 



 





 



 



You can see the yellow pollen on the stamens.



The stamens are the male part of the flower. Stamens produce pollen. The carpel is the female part of the flower. In this photo, the carpel is in the middle of the stamens. Some flowers have only one carpel. But others have many.


Flowers are everywhere



 



Flowers are many shapes, sizes and colours. Some are big and colourful. Others are tiny. Some flowers look like leaves. Even trees and grasses have flowers. Most plants have flowers so they can make seeds. Seeds can grow into new plants.



 



 



 





 



 



This big pink rose is easy to see.



The goal of every plant is to make the next generation of plants. Most plants do this by producing seeds. Flowers contain all the parts that a plant needs to make seeds. Insects and animals help too. This flower’s bright colour and strong sweet scent make it easy for them to spot.



 



 





 



 



This is the world’s biggest flower.



The Rafflesia flower is the world’s biggest flower. It is found in the jungles of Malaysia and can grow up to one metre wide. Instead of growing in the ground, it attaches itself to other plants. It smells of rotting meat!



 



 





 



 



One sunflower is made of lots of ting flowers.



Flowers come in all shapes and sizes. Tulips have one bell-shaped flower at the top of the stem. Foxgloves have lots of flowers all the way up the stem. A sunflower looks like one big flower. If you look closely you will see that it is made up of lots of tiny flowers, called florets.



 


How do plants breathe?



 



 



Most living things need air to live. You cannot see the air, nut it is all around you. You can feel it when the wind blows. Animals and plants breathe in and out all the time. Without air they would die. Plants need to breathe so they can make food.



 



 



 



 





 



 



Animals and plants need different parts of the air.



Air is made up of nitrogen, oxygen, and carbon dioxide. Plants take in carbon dioxide. They use the carbon to make food and release oxygen back into the air. Plants do not breathe in and out in the same way as animals. Instead, they absorb carbon dioxide from the air.



 



 


Continue reading "How do plants breathe?"

How do plants feed?



 



Plants make their own food. They do this in the green parts of their leaves. Most plants need sunlight to make food, so they grow toward the sun. Plants also need air and water to make their sugary food.



 



 



 



 





 



 



 



Plants only make food in the daytime when there is light.



To make food in their green leaves plants need water, carbon dioxide, and sunlight. A chemical in leaves called chlorophyll absorbs the energy from sunlight. It uses this energy to turn the carbon dioxide and water into sugar. It is chlorophyll that makes leaves look green.



 



 





 



 



Sunflowers turn their heads to follow the sun as it crosses the sky.



Plants compete with each other for light. They angle their leaves and flowers to catch as much sunlight as possible. If there is not enough light, they grow tall and thin.



 



 



 





 



 



 



This picture shows how plants make food.



Plants need sunlight, water and carbon dioxide to make food. The way plants make their sugary food is called photosynthesis.


Making new plants



 



 



Most plants have flowers so they can make seeds. There is a new plant with a tiny root and shoot inside every seed. There is also some food for the new plant in the seed. A seed needs water and light so it can start to grow.



 



 



 



 





 



 



 



Plants need sunlight, soil and water to grow.



Once a seed has begun to sprout it usually needs soil, water and sunlight so it can grow from a seedling into a healthy plant. Some plants make new plants by sending out stems that grow roots and turn into new plants. The shoots they send out are called runners.



 



 



 





 



 



Tulips grow from a bulb.



Some new plants grow from bulbs or corms. An onion is a bulb. When a bulb first grows, the new plant gets energy from the leaves of the bulb.



 



 



 



 





 



 



 



Bean plants grow from a seed.



Seeds do not grow until the conditions are right. When a seed finds the right conditions, it will grow a root and a shoot. Some coconut palm seeds float out at sea for months before they reach a place to grow.


Where do plants live?



Plants grow all over the world. They make the best use they can of the soil, water and sunlight. Where it is hot and wet, the trees grow very tall. Where it is cold and windy, the plants are very small.



These plants grow on a mountain.



Alpine plants have small leaves and thick stems to help them survive on a cold, windy mountainside.



 





 



 



These trees grow in hot, wet places.



Trees in hot, steamy rainforests must be tall to reach the sunlight.



 



 



 



 





 



Seaweed grows in the sea.



Seaweed has adapted to living in salt water. Some seaweed has pockets filled with air on its leaves. This helps it to float near the surface so that sunlight can reach it.



 





 



 



This plant is growing on another plant.



This is a mistletoe plant. It is growing on an apple tree. It has green leaves so it can make its own food, but it also takes food and water from the tree. It grows high up on the tree so it has plenty of light. Mistletoe does not usually kill the plant it lives on. If the apple tree dies, so does the mistletoe.


Plant survival



 



 



 



Plants can live almost anywhere. They live in dry deserts. It may not rain there for years. Cactus plants can live in hot deserts. They have thin, sharp leaves, thick skins and long roots. They suck up water from far under the ground.



 



 



 



 





 



 



This is a very large cactus. It stores water in its thick stem.



Deserts can be cold and dry or hot and dry. Plants can live in both hot and cold deserts, but they have to be very tough. They need a way to store water for a long time. They do this by having a thick stem and skin, and thin spikes instead of broad leaves. Thin leaves lose less water than broad leaves.



 



 



 



 





 



 



 



Some plants survive in muddy swamps.



Mangrove trees grow along tropical coasts in salt water. Mangroves have branches which send roots down into the water. Eventually, the stilt - like roots support the leafy tree above the water and hold it safely in place.



 



 





 



 



Seeds survive for a long time in the dry desert.



When rain falls on a hot desert, plants spring to life. Seeds buried in the sand grow into flowering plants. In just a few weeks they can produce seeds and die back. The seeds lie dormant in the ground for many months until the next rains.



 


Trees



 



 



Trees are the biggest plants of all. There are three kinds of trees – palm, evergreen and deciduous trees. The trunk of a tree is covered with bark. You can tell the age of a tree by counting the rings on a tree stump. Some trees can live for 4,000 years!



 



 



 



 



 





 



 



Some trees keep their leaves all year. They are evergreen.



Most pine and fir trees are evergreen. They have cones and are called conifers. Cones are the flowers of the conifer tree. The leaves on conifers are called needles. A few needles drop off every day and new ones grow all year round.



 





 



 



 



Some trees lose all their leaves in autumn.



In autumn, the weather becomes colder and there are fewer hours of sunshine. This makes the leaves of some trees change colour and fall off. Trees that lose all their leaves after they turn brown in the autumn are called deciduous trees. Oak and beech trees are deciduous.



 



 





 



 



Roots grow down to find water.



A tree’s roots can spread wider under the ground than the branches spread above the ground.



 


Grasses



 



 



 



Grass plants grow all over the world. Some grasses are taller than people, but other kinds of grass only grow a few centimeters high. Grasses have roots, stems, leaves and flowers. Grasses need sunlight and water to grow well.



 



 



 



 



 





 



 



 



Some animals eat this thick bamboo.



Bamboo is a very thick, fast-growing grass. Some bamboo can grow five centimeters in just one hour! There are about 8,000 species (types) of grass. Different kinds of grasses grow in different parts of the world. Some grasses or cereal crops, such as wheat, rice and oats, can give us food.



 



 



 





 



 



Some animals eat grass, but it soon grows again.



There are huge grasslands in Africa where zebra graze, but grass isn’t only used as food. On sand dunes, marram grass is grown to stop the sand from blowing away.



 



 



 





 



 



This grass has a very long stem.



Grasses grow quickly when there is enough water. As long as the roots have not been pulled up, grasses can go on growing even when the leaves and stems have been cut or eaten by animals.


Moss, lichen and fungus



 



 



 



Mosses, lichens and fungi do not have flowers. Without flowers they cannot make seeds. Their new plants grow from spores instead. Mosses, lichens and fungi do not need to grow in soil. Mosses make their own food. Fungi feed on the dead things they grow on!



 



 



 



 



 



 





 



 



A patch of moss is made up of hundreds of tiny moss plants.



Moss can grow on the ground, on rocks or on rotting logs in cool, damp places. There are nearly 10,000 different species of moss. They are usually small plants but in tropical parts of the world, some mosses can reach 70 cm tall.



 



 





 



 



 



Lichens can grow on trees or on rock.



Many tiny lichen plants grow side by side and form larger patches of colour. Lichens are made of two types of plants, usually fungi and algae.



 



 



 



 



 





 



 



 



Fungus grows on dead leaves, trees and old food.



A fungus has no green parts and cannot make its own food. Mushrooms, toadstools and moulds are fungi. Fungi feed off the rotting parts of plants and animals they grow on. Although some of them are edible, it is best to avoid any you come across in the wild. Some toadstools can kill a human.


Plant protection



 



Many plants cannot grow or make seeds if their stems and leaves have been torn off or eaten by an animal. Some plants have leaves that taste bitter. Other plants have thorns, prickles or sharp leaves to keep them safe.



 



 



 



 





 



 



This plant has thorns to keep animals away.



If plants are to stay alive they have to protect themselves. Some plants do this by having prickly thorns. Thorns are special short, sharp branches. Other plants, such as holly, protect themselves by having spiny leaves. If an animal tries to eat a spiky plant, it will soon be scared off!



 


Continue reading "Plant protection"