Systematic Botany of Flowering Plants

A New Phytogenetic Approach of the Angiosperms of the Temperate and Tropical Regions

R E. Spichiger

• Verlag: CRC Press
• Jahr: 2019
• ISBN:
  9780429530203
• Auflage: 1
• Thema: Scienze biologiche
• Thema: Botanica

The principle objective of this book is to describe a range of families of flowering plants in a sequence corresponding to current phylogenetic classification based on the most recent results of molecular systematics. The selection of families is large and comprises families of temperate European flora as well as tropical flora. They are integrated in their respective orders and keys are given to help the reader recognize them. Each family is richly illustrated, the identifying characters being shown as clearly as possible. A glossary complements the overall didactic qualities of this reference.

CHAPTER 1

HISTORY OF BOTANICAL CLASSIFICATION

1.1. VERNACULAR CLASSIFICATIONS, PARATAXONOMY

For hunter-gatherers, whether those of the Palaeolithic or those of the 21st century, the plant world is the source of food, fibre, building material, medicine, various toxins, and other products. The plants that furnish us with these products are the subject of vernacular classifications, i.e., those based on local names and concepts. These descriptive concepts use primarily characters such as potential use, general attraction, ecology, wood or leaf odour, the characters of exudates (sap, latex), the way in which the bark is peeled or scraped, or symbiosis with animals (e.g., ants). Such empirical classifications are called parataxonomies.

These vernacular classifications generally ignore the characters used primarily by scientific taxonomists, such as floral organs, except when they are exploited locally or are spectacular in form, colour, or odour. Despite this, it must be remembered that these empirical means of identification are precise and that in most cases the vernacular name corresponds to a scientific taxonomic concept (family, genus, sometimes species). In tropical regions, modern botanists adopt such means of identification for the purpose of a preliminary grouping of the material collected. Before being identified definitively in a botanical institution, samples are classified in the field into morphospecies with the help of local parataxonomists, i.e., into identical biological entities, or at least those having an identical local name.

The disadvantage of these local taxonomies is that they use a regional language that is unsuitable for global transmission of the information.

Even though parataxonomic classifications were dismissed by scientists of the 18th and 19th centuries, they have contributed precious information on the medicinal or other traditional uses of plants to modern floristic studies and monographs.

1.2 PREMISES OF CLASSIFICATION: FROM ANCIENT TIMES TO THE MIDDLE AGES

Aristotle (384–322 BCE) was the father of biology and in particular, classification. He used the concepts of genus and species to designate a biological entity within the framework of his Categories (see later, under Linnaeus) and to classify his Substances “in a gigantic burgeoning of beings”. Although these biological entities do not correspond to our present taxonomic concepts, they are nevertheless the result of an extremely modern scientific approach. Aristotle described the natural order in the form of a series beginning with simple organisms, through more complex organisms, and ending with man. Aristotle’s typological classification, based on the Platonic concept of archetype, definitively influenced biological classification.

From ancient times to the Middle Ages, classifications were based mostly on the use of the plant, its alimentary, aromatic, medicinal, or toxic properties. Some of the authors of classifications are mentioned below.

Theophrastus (370-285 BC) was a Greek philosopher and disciple of Aristotle. He has been called the “father of botany”. He established an artificial classification into four principal groups: herbs, sub-shrubs, shrubs, and trees. He identified 500 plants and recorded some morphological differences (e.g., corolla, position of ovary, types of inflorescence). His work was used as a reference until the end of the Middle Ages.

Pliny (23–79 BC), a Roman naturalist, wrote Historia Naturalis, an encyclopaedia in 37 volumes, nine of which addressed medicinal plants. Pliny conformed to the botany of Theophrastus while compiling information from other Roman authors. The approximately 300 plant names that he added to what was already known reveal more poesy than biological reality.

Dioskorides (1st century BC), a Greek military physician in the Roman army, transmitted his knowledge through Materia Medica. The work described 600 medicinal plants, of which 100 were new in relation to the catalogue of Theophrastus. The work of Dioskorides was a reference in the field of medicine for 1500 years.

From the beginning of the Common Era to the 17th century, the natural sciences declined in the west, suspected by the Church of diabolic deviationism. Biologists were also alchemists and doctors, but their work always seen as heresy.

One example was the philosopher Albertus Magnus (1193–1280), who was the teacher of St. Thomas Aquinas. Albert was also an alchemist and described many plants in his De Vegetans. He was the first to differentiate Monocotyledons and Dicotyledons from the structure of the stem. According to Albert, the function of an organ determined its form. It was thus ideal for classification. He established a consistent method of delimiting taxa on the basis of this single criterion, unlike what Aristotle and Theophrastus advocated.

1.3. THE FIRST SCIENTIFIC CLASSIFICATIONS: THE 16TH AND 17TH CENTURIES

The discovery of the New World made available to naturalists new material that had little to do with the European references. Botany became a more abstract science. The invention of the printing press facilitated the dissemination of information. The need for a more precise classification was felt, because the new plants could not be named according to their properties or general appearance, since most often they had not been observed in their original environment. The dried, conserved, or sometimes illustrated plant became a reference material. The appearance of the plant, often seen under the microscope, replaced its feel and odour as the most important characteristic. The variability of the floral apparatus, which could best be observed through optical instruments, made it possible to distinguish plants that were vegetatively similar. Plants could be more precisely described; they could be measured. The drawings of Leonardo de Vinci and Albrecht Dürer are remarkable for their scientific precision. There were also other botanists during this period.

Otto Brunfels (1464–1534), a German herbalist, described useful and medicinal plants and illustrated them meticulously. He distinguished flowering plants from non-flowering plants.

Luca Ghini (1490–1556) is considered the inventor of the herbarium, also called the herbarium vivum, hortus siccus (dry garden), or hortus hiemalis (winter garden). He helped establish the botanical gardens of Pisa and Florence, the first European gardens designed for the study of plants.

Jerome Bock (1498–1554), Leonhard Fuchs (1501–1566), and Valerius Cordus (1515–1544) are other German herbalists of the 16th century, to whom we owe many descriptions and illustrations from living material (flowering and fruiting plants).

Andrea Caesalpino (1519–1603), a student of Ghini, proposed new subdivisions for the classification of Theophrastus: 1500 known plants grouped in 15 classes according to their habitats and certain vegetative and carpological characters of seeds and flowers. He rejected the use of plant properties for classification and identification and he proposed a description based on number and form. He established his system primarily on the variations of the fructiferous organ. Caesalpino was the first botanist to understand that the embryo is a fundamental character in systematics.

The Bauhin brothers were contemporaries of Caesalpino and made a longstanding impact on plant classification. Johannes Bauhin, the younger of the two (1541–1612) and also called the “father of botany”, was a Huguenot who took refuge first at Basle. He had worked with Fuchs at Tubingen and with Rondelet at Montpellier. Settled at Geneva as a “doctor of the State” (1568-1570), he compiled the first floristic study of importance of the Geneva region (Burdet et al., 1990). His Historia Plantarum Universalis (posthumously published, 1650–1651) contains descriptions of 5000 taxa. It was the first time that a large number of European plants were described in a truly identifiable manner. Bauhin probably described many Swiss and Genevan plants to Jacques Dalechamps (1513–1588), the first collector known in the Genevan basin. Kaspar Bauhin (1560–1624), a Genevan pastor and doctor, founded the first botanical garden of that city. He published in his Pinax (1623) a list of 6000 plants with their synonyms. He invented a binomial system of nomenclature to name the plants that he described. This system was taken up and systematized by Linnaeus. Bauhin used the notions of genus and species. The generic names given by Bauhin became commonly used thanks to Linnaeus. To distinguish the taxa, Bauhin did not limit himself to a single character as did Caesalpino but used several. He did not invent systematics, but his Pinax indisputably marks the beginning of modern floristics (De Wit, 1994).

John Ray (1627–1705) described 18,000 species. He was the inventor of the modern concept of species, which he defined in his Historia Plantarum (1686–1704). He took up those ideas of his predecessors that he found interesting—those of Bauhin among others—and defined the species according to their morphological resemblances using a large number of characters. He categorized Cryptogams under the name Imperfectae. He was the first botanist to use the major divisions of Monocotyledons and Dicotyledons. He originated natural classification, i.e., a classification using many characters. He did not, however, retain the binomial concept of Bauhin. He would greatly influence the Jussieus and Candolles (section 1.5). He introduced into systematics the dichotomic method (De Wit, 1994). For Genevan botany, Ray sketched out the first flora of the region (Burdet et al., 1990).

Pierre Magnol (1638–1715), professor of botany and director of the botanical garden of Montpellier, had occasion to meet Ray and present to him his concept of Familia. The families that Magnol proposed are still being used.

Joseph Pitton de Tournefort (1656–1708), a friend of Magnol, introduced the modern concept of genus, which he defined as the basic unit of classification, considering species to be varieties of genus. This generic concept was taken up by Linnaeus. Tournefort grouped 10,000 species into 700 genera and 22 classes. His classification is mainly based on the corolla, as was recommended by Auguste Quirinus Rivinus, Bachmann in German (1652–1723). He used the concepts of “Apetales”, “Monopetales” (= Gamopetales or Sympetalae), and “Polypetales” (= Dialypetalae). His system was strictly dichotomic. He attached little importance to the number of cotyledons.

Until the Renaissance, use and environment were considered the primary factors for plant classification. To this were added a certain number of morphological characters from the 16th century onward, thanks to the invention and development of the microscope. In the 17th century, Ray recommended the use of the largest possible number of characters. Thus, before Linnaeus, the modern concepts of Cryptogams and of Monocotyledons and Dicotyledons were established, as well as the bases of the binomial nomenclature (G. Bauhin) and the notions of family (Magnol), genus (Tournefort), and species (Ray).

1.4. LINNAEUS: THE INVENTION OF MODERN NOMENCLATURE

Carl von Linnaeus (1707–1778) was professor of botany and medicine at the University of Uppsala (Sweden). He is considered the father of taxonomy. He invented a classification based on the differences of sexual organs: 24 classes according to the number (Monandria, Diandria, etc.), fusion, and length of stamens and according to the number of styles. Such a classification, based on a restricted number of characters, is described as artificial. Linnaeus was aware that his system was not natural, but in practical terms it made it possible to classify all the botanical material known at that time. He improved the binomial system already proposed by G. Bauhin, took up the notion of genus according to Tournefort, and gave the species its modern significance based on the concept of Ray.

Linnaeus magnificently assimilated the data of his predecessors. The incomparable influence of his work lies in, among other things, a masterful integration of the data of the past. Until then species were described by short Latin phrases of a few words, called polynomials. Linnaeus desired to name all the existing minerals, plants, and animals. He used this polynomial system in Species Plantarum (1753), making an innovation that would be the basis of the modern binomial nomenclature: in the margin of the polynomial descriptions of each species in the Species Plantarum, he added a summary made up of a single word that, combined with the generic name, would give a two-word abbreviation (binomial) of the polynomial description. The modern nomenclatural system was born. An example is the daisy called Bellis scapo nudo unifloro or Bellis sylvestris minor according to authors before 1753. These names are polynomials. In Species Plantarum, Linnaeus called it Bellis perennis, a scientific name that it still goes by.

Linnaeus wrote three encyclopaedic works in botany:

• Systema Naturae (1735), a presentation of his system of classification of three kingdoms of nature: mineral, plant, and animal.

• Genera Plantarum (1737) (description of plant genera); in the appendix of the sixth edition (1764), he added a list of 58 “natural orders”.

• Species Plantarum (1753), a catalogue and manual for the identification of plants known at the time.

With Species Plantarum, Linnaeus became the first author of a world flora, a gigantic work combining all the botanical information available at the time. In addition, the work represented the point of departure for modern nomenclature of most plants.

Until that time, and for Linnaeus as well, living nature was a fixed and definitive divine creation. The essentia had been created once and for all during the events cited in Genesis, or by a divine original impulse described by Aristotle and the Ancients. For Linnaeus, who was directly influenced by Aristotle, one essentia, i.e., any group of similar organisms, was distinguished from another essentia by differentia. The definitio is the description of the essentia. Thus, the binomial nomenclature precisely reflects the generic essentia reduced to a single word, the genus name, to which is added another single word, the species epithet, indicating the specific differentia. This type of artificial classification, essentialist and fixed, reached its peak with Linnaeus and his disciples (Thunberg and Willdenow).

1.5. NATURAL CLASSIFICATIONS AND BASES OF MODERN SYSTEMATICS: THE FRENCH SCHOOL, CANDOLLE, BENTHAM AND HOOKER

At the end of the 18th century, many discoveries were made by naturalists exploring the intertropical zones and the southern hemisphere. The cultivation of plants in greenhouses in large metropolitan botanical gardens, a reflection of the ongoing colonial expansion, and advances in the means of observation led to a deeper knowledge of anatomy and physiology. Bo...

Inhaltsverzeichnis

• Cover
• Half Title
• Title Page
• Copyright Page
• Preface to the English Edition
• Acknowledgements
• Table of Contents
• Introduction
• Chapter 1. History of Botanical Classification
• Chapter 2. Species and Speciation
• Chapter 3. Floras and vegetations
• Chapter 4. From Algae to Angiosperms
• Chapter 5. Evolution and Classification of Plants with Seeds
• Chapter 6. Selected Orders and Families
• Descriptive Plates of Families
• Glossary
• Key to Identification of Tropical Families by Observation of Vegetative Characters
• Taxonomic Index
• List of Species Illustrated with Colour Photographs on the CD-ROM
• General outline of the taxonomic organization of the book, with a list of the families described