Colour Atlas of Woody Plants and Trees

Bryan Bowes, Bryan G. Bowes

• Publisher: CRC Press
• Year: 2020
• eBook ISBN: 9781351110778
• Topic: Sciences biologiques
• Subtopic: Écologie

Trees and plants are important components of the human environment having significant presence beyond agricultural and recreational values. Colour Atlas of Woody Plants and Trees presents a photographic compilation of morphological features of trees and shrubs giving attention to their unique aspects not presented in existing books. By increasing awareness to users through high quality, full-color photographs and informative text, this book demonstrates the enormous diversity of vascular trees and plants living today.

Features:

• Full color atlas offers concise, but highly informative text accompanied by over 200 high-resolution digital tree images

• Contains images of the anatomy of tree structures and evolution of the most important features of trees

• Presents information on the varied structure and morphology exhibited by trees and demonstrates their vital importance in the current struggle for the survival of our human society

• Surveys the most important morphological features of plants, shrubs and trees

• Presents aspects of plants and trees both common and rarely seen in nature

Bryan Geoffrey Bowes is a retired Senior Lecturer in the Botany Department at Glasgow University and was a Research Fellow in ETH Zurich, Harvard University, and University of New England, Australia. His research interests encompass plant anatomy and ultrastructure, plant regeneration, and morphogenesis in vitro.

1 Introduction

Land Plants

All land plants contain chloroplasts, which colour their tissues, as seen in the newly expanding green leaves (Figure 1.1) of Aesculus hippocastanum (Horse Chestnut). Chloroplasts are the minute organelles – visible in detail under an electron microscope (Figure 1.2) – where photosynthesis occurs.

FIGURE 1.1

FIGURE 1.2

Brief Survey of Ancient Land Plants

A layer of chert, a rock rich in silica, is located at Rhynie in Aberdeenshire, Scotland. The rock’s microscopic structure was first investigated by Kidston and Lang, working in Glasgow University between 1917 and 1921. Both they and later workers reported on the discovery of fossilised remnants of an early land flora which existed near Rhynie some 410 million years ago (mya). The plant remains were petrified in situ by ash from volcanoes which polluted local pools of water where, at their margins, various very small primitive land plants were then growing. The remains of this Rhynie flora (preserved in the rocky chert) contain randomly preserved fragments of some of the earliest known land plants. Figure 1.3 shows the polished surface of a chert block in which plant debris is clearly visible; in Figure 1.4 a section of the rock is viewed under a light microscope, whereas a longitudinal section of the spore-containing capsule of Aglaophyton – one of these primitive plants – is illustrated in Figure 1.5.

FIGURE 1.3

FIGURE 1.4

FIGURE 1.5

From these and other primitive land plants, a varied land flora evolved, and, by the later Carboniferous Period, a rich arboreal flora existed; numerous remains of this flora have been identified from locations throughout the world. One such site is illustrated in Figure 1.6, which shows a fossil-rich limestone quarry on the outskirts of Glasgow, Scotland. In Figure 1.7 a fragment of the limestone debris lying at the quarry base reveals the petrified remains of a Lepidodendron (Stigmaria) root, with numerous broken-off stubs of its rootlets visible on its surface, whereas others pass out into what was the original soil surface.

FIGURE 1.6

FIGURE 1.7

In the rich Carboniferous plant deposits located in Scotland, further important fossils have been discovered. Figure 1.8 shows the protective shelter built around Fossil Grove at Victoria Park, Glasgow. During the laying-out of the recreation grounds at Victoria Park in the 19th century, workmen exposed the petrified stumps (still lying in situ) of several large trees, which were then identified as Lepidodendron fossils. Due to their exceptional scientific importance, a protective shelter was erected around them and the surrounding rock was carefully chiselled away to reveal their internal stone casts. On the viewing platform of this shelter, a group of University undergraduates are studying several fossil casts of the tree remains, which lie exposed on the rock floor. In Figure 1.9 a more detailed view of one of these casts reveals how, at the original swampy ground level, the vertical tree trunk divided dichotomously (equally) into horizontal roots. They ran for several metres along the surface of the lagoon where this stand of trees was growing. Figure 1.10 is a diagrammatic reconstruction of a mature specimen of Lepidodendron. Such trees are estimated to have reached some 30 m in height, with their closely crowded trunks some 1 m wide at the base. The tree trunk rarely branched, except at its tip, which bore branches bearing clusters of narrow leaves and reproductive cones. The trunk’s layer of bark (composed of persistent photosynthetic leaf cushions on its surface; Figure 1.11) played an important role in mechanical support for the tree. Unfortunately, during the excavation of these fossils, their bark was destroyed by the chiselling away of the enclosing rock matrix. Within the trunk there was some central secondary wood composed of radially arranged tracheids (Figure 1.12).

FIGURE 1.8

FIGURE 1.9

FIGURE 1.10

FIGURE 1.11

FIGURE 1.12

By the Carboniferous Period, ferns bearing seeds were also present in the flora: Figure 1.13 shows a rock section with the stem of the seed fern Lyginopteris oldhamia revealing its well-developed secondary xylem cylinder, enclosing a prominent pith. Figure 1.14 shows a fossilised seed of Lagenostoma ovoides, which is surrounded by a thick carbonised seed coat.

FIGURE 1.13

FIGURE 1.14

By the later Triassic Period (some 200–250 mya), extensive tropical forests of large coniferous trees had develo...

Table of contents

• Cover
• Half-Title
• Title
• Copyright
• Dedication
• Contents
• Preface: Trees and Why We Love Them
• Acknowledgements
• Author
• Chapter 1 Introduction
• Chapter 2 Anatomy of Trees and Woody Plants
• Chapter 3 Roots of Trees and Woody Plants
• Chapter 4 Tree Leaves: The Green Sugar Factory
• Chapter 5 Reproduction in Trees and Woody Plants
• Chapter 6 The Importance of Trees in the Environment
• Chapter 7 Trees and Their Links with Human Cultures
• Index