GenreGenre Comprehension SkillComprehension Skill Text FeaturesText Features Science ContentScience Content Nonfi ctionNonfi ction PredictPredict • Captions• Captions PlantsPlants • Labels• Labels • Glossary• Glossary Scott Foresman Science 2.1Scott Foresman Science 2.1 ì<(sk$m)=bdhhbi<ì<(sk$m)=bdhhbi<ISBNISBN 0-328-13771-50-328-13771-5 +^-Ä-U-Ä-U+^-Ä-U-Ä-U
Vocabulary Extended Vocabulary What did you learn? adapt cactus environment evaporation 1. What are the two ways desert flower oasis plant roots grow? leaf petals nutrients pollination 2. What do spines do? prairie surface roots 3. Some desert stem plants have folds in their skin. Write to explain how folds helpby Michael MacGillivray desert plants store water. Use words from the book as you write. 4. Predict What will happen to desert plants after it rains? Picture Credits Every effort has been made to secure permission and provide appropriate credit for photographic material. The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions. Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd). Opener: Okapia/OSF/Photolibrary. 2 (R) Digital Vision; 4 David Whitten/Index Stock Imagery; 10 George D. Lepp/Corbis; 15 (TL) Gerry Ellis/Minden Pictures; 17 Okapia/OSF/Photolibrary; 20 Phil Banko/Corbis; 23 Dave G. Houser/Corbis. Unless otherwise acknowledged, all photographs are the copyright © of Dorling Kindersley, a division of Pearson. ISBN: 0-328-13771-5 Copyright © Pearson Education, Inc. All Rights Reserved. Printed in the United States of America. This publication is protected by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permission(s), write to Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025. 3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06 05
What You Already Know The roots of a plant grow The environment of a plant is the place into the soil. They hold the where it lives. Plants have adapted to live in plant in place. Roots also take different kinds of places. Prairies, woodlands, in water and nutrients. Plants and marshes are places where plants can grow. need nutrients to live and grow. The stem holds up the plant. Deserts are hot and dry environments. It also brings water and Even so, plenty of plants can be found in the nutrients to the leaves. Leaves desert. Read on to fi nd out how desert plants use sunlight, water, and air to have adapted to live where it is hot and dry. make food. Some plants have fl owers. Monument Valley, Flowers make fruit and seeds Arizona, USA young tree that can grow into new plants. Scattering helps carry seeds to new places where they can grow. Some plants have cones instead of flowers. Their seeds come from the cones. 2 3
Plants in the Desert Most deserts get less than ten inches of rain each year. Some deserts might not get any rain at all for many years. Others get many inches There are deserts all over the world. of rain all at once. Even though there is only a Most deserts are very hot and dry. We think little water in these areas, many types of plants of deserts as empty places full of sand, but live in the desert. These plants depend on rain most deserts are only partly made of sand. and underground water to survive. As long as there is water, deserts can be a home for many living things. plants growing in a desert 4 5
Quick to Flower fl owers blooming in the desert Some parts of a desert can become very colorful after it rains. Many plants make fl owers only when it rains. The fl owers that bloom hold seeds. New plants can grow from the seeds. Flower petals lose their water fast in the hot desert fl owering cactus sun. The water becomes a gas and goes into the air. This is called evaporation. Petals dry up and fall off when water evaporates from them. Some plants spring to life when it rains. These plants bloom very quickly. They only live for a few weeks or months after they bloom. The seeds of some of these plants can last up to three years waiting for rain. 6 7
Pollination and Seeds The century plant can grow to be ten to fourteen feet tall. It has flowers that bloom near the top. The century plant was named by people Some plants use their flowers to make new who thought that it bloomed once every one plants. Their fl owers make a fi ne powder called hundred years. This is not really true. pollen. Desert animals fly from fl ower to fl ower. Small century plants can bloom after They carry the pollen from one plant to another. three or four years. Some big This is called pollination. ones bloom after forty Pollen helps new seeds start to grow. or fi fty years. Sometimes the seeds are in a fruit that the plant makes. The agave (ah-GAH-vay) cactus has a Century plant yellow fl ower that makes a smooth green fruit. fl owers are mostly yellow. This fruit can hold many seeds. the yellow fl ower of an agave cactus 8 9
Roots Desert plants use their roots to get as much water as they can. Since there is not a lot of water, desert plants grow far apart. This way, the roots do not have to fight each other for the little bit of water The haworthia has long, deep roots. that there is. Some plants have roots that grow near the surface or top of the The saguaro ground. These roots spread out. (sah-GWAH-roh) They take in water when it rains. cactus has roots Other plants have roots that grow near the surface of the deep into the earth. These plants ground. The roots drink take in underground water. in the rain. This cactus A plant with deep roots can get also has other roots that water more of the time. It does wrap around rocks. not have to wait for rain. These small roots help keep the large, heavy All plants must saguaro cactus from share water. falling down. 10 11
Storing Water water-storing part Cactus plants grow in many deserts. A cactus is a plant that has special ways to store water. Many plants store water in their stems and leaves. Cactus plants have thick, waxy skin. This skin keeps water from evaporating. It also helps protect the plant from the Sun. Some desert plants have folds in their skin. Folds let these plants grow like balloons when they take in a lot of water. The plants go back to normal size when the water is gone. tough skin barrel cactus The skin of a barrel cactus has folds and tough spines. The spines grow in bunches. The barrel cactus can store a lot of water. It gets bigger when it holds water. It grows slowly and can live more than one hundred years. 12 13
Leaves and Spines Plants lose water in the Sun and wind. The leaves of desert plants are made to keep water in. Many desert plants only have a few leaves. Others have small leaves. Some plants drop their leaves when it gets too dry. Other The kookerboom tree only grows plants have leaves with small holes to take in leaves at the top water. The holes open at night, when it is cooler, of its branches. and close during the day, when it is hotter. Most cactus Some desert plants have plants do not leaves. Some do not. have leaves. Plants bunny-ears without leaves use cactus their stems to make food. agave Cactus plants have sharp plant spines. The spines grow on the plant’s skin. Spines block the wind. They can also keep the Sun off the plant with their tiny shadows. In these ways they help keep water in the plant. kookerboom leaves 14 15
The baby-toes cactus has very special leaves. Most of the plant is under the ground, but the leaves stick up. The leaf tips are see-through. They let light into the rest of the leaf. The glossy green leaves of the desert rose will fall off if the plant does not get enough water. When water can be found, its leaves grow again. The leaves of the desert rose also help the plant stay safe. The parts of this plant, including the leaves, are poisonous. desert holly desert rose The desert holly is made to live in the dry desert. This plant keeps salt on its prickly leaves. The salt is like a sunblock. It helps the plant stay cooler. The desert holly can sometimes drop its leaves to save water. baby-toes cactus 16 17
Amazing Plants The Joshua tree is an amazing desert plant. The Joshua tree grows to forty feet. One of the oldest Joshua trees is more than Joshua tree nine hundred years old! The Welwitschia (wehl-WHICH-ee-uh) plant lives even longer than the Joshua tree. It starts with a pair of wide, long leaves. These leaves grow and split. Then it looks like there are more than two leaves. These plants can live to be one to two thousand years old! It is not easy to live in the desert. Many desert plants are small and have short lives. Welwitschia But some desert plants are amazing because plant of their big size and long life. 18 19
An Oasis Lots of plants can grow in an oasis because there is water. Sometimes, palm trees will grow in an oasis. They stand tall over the land and An oasis is a place in the desert with water. can be seen from far away. They let people know The water in an oasis comes from rain or snow where an oasis is. If an oasis is large enough, high up in the mountains or hills. It travels through people can live on it. rocks under the ground. If the water stops at a low Another kind of oasis is a stream that starts place in the desert, then an oasis can form. in the mountains and flows through the desert. Plants also grow along this kind of oasis. water in an oasis 20 21
Desert Plants Many plants have adapted to grow in hot and dry deserts. Colorful fl owers bloom after rain and make the desert come alive. Flowers help make new plants. Desert animals move pollen from fl ower to fl ower. This is called pollination. Plants can grow seeds when pollen moves. Some plants have roots that are near the top of the ground. These plants need to take in rain. Other plants have deep roots that get water from under the ground. Desert plants find many ways to store water. Some plants use spines to keep the water in. Some desert plants can grow very big and very old. The Joshua tree and the Welwitschia are two of the oldest growing plants. Palm trees grow very tall. They can grow near an oasis. People can live on an oasis if there is enough room. Deserts may seem empty at first. But if you know where to look, you will find that they are full of life. 22 23
GlossaryVocabulary Extended Vocabulary What did you learn? adapt cactus environment evaporation 1. What are the two ways desert flower oasis plant roots grow? cactus a desert plant with very sharp leaf spines petals nutrients pollination 2. What do spines do? evaporationprairie to turn into a gassurface roots 3. Some desert stem plants have folds in their skin. oasis a place in the desert with water Write to explain how folds help and plants desert plants store water. Use words from the book as you write. petals parts of a fl ower 4. Predict What will happen to pollination carrying pollen from one fl ower to desert plants after it rains? another so new plants can grow surface the top part of something Picture Credits Every effort has been made to secure permission and provide appropriate credit for photographic material. The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions. Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd). Opener: Okapia/OSF/Photolibrary. 2 (R) Digital Vision; 4 David Whitten/Index Stock Imagery; 10 George D. Lepp/Corbis; 15 (TL) Gerry Ellis/Minden Pictures; 17 Okapia/OSF/Photolibrary; 20 Phil Banko/Corbis; 23 Dave G. Houser/Corbis. Unless otherwise acknowledged, all photographs are the copyright © of Dorling Kindersley, a division of Pearson. ISBN: 0-328-13771-5 Copyright © Pearson Education, Inc. All Rights Reserved. Printed in the United States of America. This publication is protected by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permission(s), write to Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025. 3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06 0524
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