Botany For Gardeners

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An in-depth understanding of plant life, specifically those used in gardening.

Text of Botany For Gardeners

  • Botany for GardenersREVISED EDITION Brian Capon

    $19.95/ 14.99 GARDENING & HORTICULTURE / Reference

    Botany for Gardenersoffers a clear explanation of how plants grow.

    What happens inside a seed after it is planted? How are plants structured? How do plants adapt to their environment? How is water transported from soil to leaves? Why are minerals, air, and light important for healthy plant growth? How do plants reproduce?

    The answers to these and other questions about complex plant processes,written in everyday language, allow gardeners and horticulturists tounderstand plants from the plants point of view.

    A bestseller since its debut in 1990, Botany for Gardeners has now been expandedand updated, and includes an appendix on plant taxonomy and a comprehensive

    index. Two dozen new photos and illustrationsmake this new edition even more attractivethan its predecessor.

    Brian Capon received a ph.d. in botanyfrom the University of Chicago and was forthirty years professor of botany at CaliforniaState University, Los Angeles. He is theauthor of Plant Survival: Adapting to a HostileWorld, also published by Timber Press.

    Author photo by Dan Terwilliger.

    For details on other Timber Press books or to receive ourcatalog, please visit our Web site, the United States and Canada you may also reach usat 1-800-327-5680, and in the United Kingdom at

    ISBN 0-88192-655-8


    ISBN 0-88192-655-8


    0 08819 26558 0 9 780881 926552


    Botany for GardenersBrian Capon


    BotGar_Cover (5-8-2004) 11/8/04 11:18 AM Page 1

  • Botany for Gardeners

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  • 001-033_Botany 11/8/04 11:21 AM Page 2

  • Botany for GardenersRevised Edition

    Written and Illustrated by


    TIMBER PRESSPortland * Cambridge

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  • Cover photographs by the author.

    Text copyright 2005 by Brian CaponPhotographs and drawings copyright 2005 by Brian CaponAll rights reserved

    Published in 2005 by

    Timber Press, Inc. Timber PressThe Haseltine Building 2 Station Road133 S.W. Second Avenue, Suite 450 SwaveseyPortland, Oregon 97204-3527, U.S.A. Cambridge CB4 5QJ, U.K.

    Printed through Colorcraft Ltd., Hong Kong

    Library of Congress Cataloging-in-Publication DataCapon, Brian.Botany for gardeners / written and illustrated by Brian Capon.-- Rev.

    ed.p. cm.

    Includes index.ISBN 0-88192-655-8 (pbk.) -- ISBN 0-88192-655-81. Botany. 2. Gardening. I. Title. QK50.C36 2005580--dc22 2004003695

    A catalog record for this book is also available from the British Library.

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    Introduction 9


    Chapter 1Cells and Seeds: Basics and Beginnings

    Cells 16Cell Walls 18Wall Structure and Cell Growth 20Growth Processes 22Meristems 22Seed Coats 24Food-Storage Structures and the Embryo 25Seed Germination 29Other Germination Requirements 31

    Chapter 2 Roots and Shoots: How Plants Mature

    Root Systems 34Root Growth 36Root Hairs and Branches 37Primary Growth in Stems 38Development of a Woody Twig 44Features of a Woody Twig 45Leaves 47


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  • 6 Contents


    Chapter 3 Inside Stems

    Herbaceous Stems 56Stem Thickening 59Other Features of Wood 64Monocot Stems 67

    Chapter 4 Inside Roots and Leaves

    A Roots Primary Tissues 71Secondary Growth in Roots 73Cellular Organization in Leaves 74Plant Cell Types 79


    Chapter 5 Adaptations for Protection

    The Garden Habitat 87Environmental Modication 88Limiting Factors 91Protection in Extreme Environments 92Protection against Animals 96Protection by Camouage 99Protection by Ants 100Wound Healing 101Chemical Protection 103Mode of Operation of Chemical Protectants 106Other Methods of Defense 108

    Chapter 6 Adaptations to Fulll Basic Needs

    Competition between Plants 109Reaching toward the Sun 110Spreading Stems 111Climbing Structures 113

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  • Contents 7

    Lianas and Epiphytes 115Supportive Roots 115Special Methods of Water Uptake 117Adaptations for Water Storage 118Underground Food- and Water-Storage Organs 120Saprophytes and Parasites 124Mycorrhizae and Root Nodules 126Insectivorous Plants 128


    Chapter 7 Control of Growth and Development

    Growth Responses to Light 134Responses to Gravity and Touch 137Other Growth Movements in Plants 140Hormones and the Aging Process 141Control of Branching and Adventitious Root Formation 143Other Hormone Effects: Synthetic Growth Regulators 144Environmental Control: Temperature 145Vernalization 147Environmental Control: Photoperiod 148

    Chapter 8 The Uptake and Use of Water, Minerals, and Light

    Osmosis: The Cells Water Pump 152Development of Root Pressure 155Transpirational Pull 156Cold Hardening 158Mineral Nutrient Needs 158Soils 163The Photosynthetic Apparatus 165Light Transformed into the Energy in Food 168The Photosynthetic Process 169Gas Exchange with the Atmosphere 172

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  • 8 Contents


    Chapter 9 From Flowers to Fruits

    Flower Parts and Their Functions 178Pollination by Animals 182Road Maps and Rewards 183Inorescences 186Pollination by Wind and Water 189Pollination Alternatives 191The Reproductive Process 193Seedless Fruits and Unusual Embryos 195Fruit Types 195Seed Dispersal 198The Cost of Reproduction 200

    Chapter 10 Strategies of Inheritance

    Genetics: The Science of Heredity 201Mitosis and Meiosis 202The Life Cycle of a Moss 203The Life Cycle of a Fern 205The Two Generations of Flowering Plants 207Chromosome Segregation during Meiosis 209Gene Segregation during Meiosis 210Consequences of Imperfection 213The Origins of Polyploidy 214Custom-made Plants of the Future 217

    Epilogue 219Appendix: Plant Names 220Glossary 224Index 234

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  • Earth has been called the green planet, a worldclothed in a mantle of vegetation that sustains all other forms of life on thistiny spot in the universe. From simple beginnings, plants evolved rstamong Earths living things and thereby established a fundamental princi-ple of nature: Plants, in one form or another, can exist forever without ani-mals, but animals cannot exist without plants.

    Plants purify the air by exchanging the oxygen we breathe with carbondioxide, which is poisonous in too high a concentration. Plants convert theenergy of sunlight into foods that sustain all animals and, from the soil,draw minerals such as nitrogen, potassium, calcium, and iron that are essen-tial for our well-being. For creatures large and small, plants provide shadefrom the sun, refuge from predators, and protection from the ever-chang-ing elements. Since the rst cells came into being millions of years ago,plants have been the connecting links in an unbroken chain of life. It is theythat have made the biosphere, the part of Earths crust where both plantsand animals exist, a place of limitless opportunity for human inquiry.

    The range of uses we make of plants is as broad as our ingenuity permits.We have exploited them for bers to make cloth, drugs to cure a multitudeof ailments, and wood to construct houses, furniture, and ships. From themwe have extracted raw materials to manufacture innumerable goods, includ-ing paper. Without that latter commodity, the detailed history of our racewould not have been recorded and so remembered, nor could knowledgehave been so easily disseminated. And culture, the possession of whichmakes humans out of animals, would never have developed beyond thebasic skills and habits of primitive peoples had we not had paper on whichto write music, poetry, and prose.

    Some of us look at plants as a source of livelihood, while others ndthem intriguing subjects for scientic study. But most enjoy plants for thesheer delight of having them in their everyday surroundings, to savor thevaried colors, textures, tastes, and aromas that they alone can offer. Plants



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  • 10 Introduction

    stimulate the senses, bring us a sense of peace and tranquility, and direct ourthoughts to contemplating the mysteries of life.

    Few gardeners share the botanists knowledge of plant biochemistry,anatomy, physiology, and intricate reproductive systems, yet all have expe-rienced the extraordinary satisfaction derived from growing owers, fruits,vegetables, and trees.

    When we work with plants, questions about them inevitably come tomind. What takes place inside a seed after we have set it in the ground?How does water travel from soil to treetops? What makes a plant becomebushy with repeated pruning? What controls seasonal owering patterns?How do plants grow, and why is light necessary to make growth happen?Over the centuries, botanists have worked to nd answers to these andother problems. Slowly, plants have revealed some of their secrets.

    Botany is a useful and rewarding study from which, unfortunately, manylaypersons are frightened away by the technical jargon that constitutes thelanguage of the science. The reader will encounter a number of scienticwords in the following pages. Some are part of the common parlance ofgardeners. For want of suitable nontechnical equivalents, others cannot beavoided when writing such a book. Each technical word, whether commonor obscure, is explained in the text and glossary, and occasional reference ismade to the G