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TAXONOMY OF VASCULAR PLANTS: Part One

03. History of Classification: Theories

hist-class3.htm

by George H. M. Lawrence, Professor of Botany at the Bailey Hortorium, Cornell University, 1951

Photo-copied by Maung Kan Tun from the original text.
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Lawrence-indx.htm

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Period 3. Systems based on form relationships
- Michel Adanson
- Jean B.A.P.M. deLamark
- De Jussieu
- De Candolle
The first publication in English language
- John Lindley
- Bentham and Hooker

Period 4. Systems based on phylogeny
- August Wilhelm Eichler
- Adolph Engler
- Richard von Wettstein
- Charles E. Bessey
- Hans Hallier
- John Hutchinson

Other contemporary systems
- Alfred Barton Rendle
- Karl Christian Mez
- Oswald Tippo

Literature
  History of Classification

 

Footnotes

UKT notes
cyathium : {rha.saung:} flowers
perianth

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Period 3. Systems based on form relationships

The second half of the eighteenth century was a period when great numbers of living plants, seeds of plants, and collections of prepared specimens were coming into Europe's botanical centers from all of the world's continents. A large proportion of these were of species new to science, each to be given a name, to be described, and placed in a classificatory system. With the increase in knowledge of the world's flora came the realization (about 1800) that there were greater natural affinities between plants than the so-called "sexual system" of Linnaeus would [{p027}]indicate. [UKT ¶]

This realization was not derived from theorizing and logic, but was made cogent by man's increased knowledge and understanding of the organography and functioning of plants. Due acknowledgement must be made to the development of optics, to the awareness of the biological significance of sex organs in plants, and to an understanding of the rudiments of floral morphology. It was near the close of the eighteenth century and at the beginning of the next that revolutionary changes in systems of plant classification first were apparent. [UKT ¶]

The new systems were called natural systems and are so in the sense that they reflected man's understanding of nature at that time. Plants were placed together because there existed a correlation of characters in common. The epoch-making work of Charles Darwin and Alfred Russel Wallace had not appeared. Modern evolutionary theories were unknown, and the concept of consanguinity of relationships was still vague (its underlying forces had been studied but not recognized by such men as Lamarck, Erasmus Darwin, Chambers, and others). The systems of this period were natural in that they served the desire of human mind for true order; but better than Tournefort, Ray, and others, they also served the practical need of a classification by functioning adequately as an aid to identification. They are not phylogenetic systems and, in the sense that the latter are natural to the extent of allegedly indicating "blood" or genetical relationships, these earlier systems are esoteric. However, this in no way detracted from their utility, and most of the great floras of the world have been based on them.

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MICHEL ADANSON (1727-1806)

Michel Adanson, was a French botanist, a member of the faculty of l'Academie des Sciences at the Sorbonne, Paris, and an early plant explorer of the tropics. His major contributions included the rejection of all artificial classifications for the natural, and the descriptions of taxa more or less equivalent to modern orders and families (the latter a unit suggested earlier by Ray); all set forth in his 2-volume work, Familles des plantes (1763) (fn027-07).

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JEAN B. A. P. M. de LAMARK (1744-1829)

Jean B.A.P.M. deLamark,  was a French biologist best known to taxonomists for his Flore francoise (1778), written in the form of an artificial key to provide a means of identifying the plants of France. In the introduction of this work he laid down the principles of his concept of a natural classification:

1. the determination [{p028}] of which plant precedes another in a natural series;
2. the rules for the natural grouping of species; and
3. the treatment of orders and families. [UKT ¶]

Lamarck is known also for his theory (known as Lamarckism) that  changes in environment caused changes in the structure of organisms ( such as new uses of parts or organs, or the loss of parts or organs through disuse), and that these changes were inherited by the offspring.

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DE JUSSIEU 

De Jussieu. An apothecary of Lyon, France, named de Jussieu had three sons: Antoine (1686-1758), Bernard (1699-1776), and Joseph (1704-1779). All three become botanists; the two elder brothers remaining in France, the youngest spending many years in South America where he went insane after losing botanical collections made and accumulated over a period of five years. [UKT ¶]

Antoine and Bernard both studied under the great French teacher-botanist Pierre Magnol (1638-1715) at the University of Montpellier. Antoine succeeded Tournefort as Director de Jardin des Plantes, Paris. Later be added his brother Bernard to the staff. In 1759 Bernard de Jussieu rearranged the plants in the garden at La Trianon, Versailles, according to a system more or less of his own devising, but with many similarities with the natural classification in Linnaeus' Fragmenta methodi naturalis and in Ray's Methodus plantarum. Here for the first time there was assembled a system that was not on the Aristotelian concept of habit that Tournefort adhered to, nor one that was artificial, as was the system of Linnaeus. [UKT ¶]

De Jussieu divided the flowering plants into groups on the basis of monocot vs. dicot, ovary position, presence or absence of petals, and fusion or distinctness of petals. He never published his system and in 1763 he called in his 15-year-old nephew, Antoine Laurent de Jussieu (1748-1836) to work with him.

Ten years later Antoine Laurent de Jussieu published his first paper proposing a new classification of plants. It represented an improved version of his uncle's system and was in form of a memoir dealing with the relationships within the Ranunculaceae. It initiated an era of natural systems, and the beginning of a period of classification that witnessed many modifications of this one system. During the following year de Jussieu published an Exposition d'un nouvel ordre de plantes in which he proposed to classify all plants on the basis of: acotyledonae, monocotyledoneae, and dicotyledoneae; the latter he divided into five groups based on corolla characters, calling them apetalae, petalae, monopetalae, polypetalae, and diclinae. This preliminary proposal of a new basis for classification, published in 1774, came to fruition in 1789 (the year of the French Revolution) in his Genera plantarum. [UKT ¶]

As a chemist, I would never forget how revolutions can get out of hand. The great French chemist Antoine Lavoisier (1743-1794), was guillotined on a flimsy charge of selling adulterated tobacco. -- http://en.wikipedia.org/wiki/Antoine_Lavoisier 121226
It was the time of King Bodawpaya (1745-1819) in Myanmarpré. In spite of the excesses of the king, the country was at its height. See Sangermano, The Burmese Empire a Hundred Years Ago

In this work, flowering [{p029}] plants were divided into fifteen classes along the lines outlined above, and these classes were subdivided into 100 orders (Ordins naturales), each of which was clearly differentiated, named, and provided with a description. A large number of his orders (i.e., families) are to be found intact in the most modern of present-day classifications. [UKT ¶]

The related taxa of Palmae, Liliaceae, Amaryllidaceae, and Iridaceae were grouped together, the Monopetalae contained those families now known as the gamopetalae, while his class Diclines irregulares (an unnatural assemblage) contained the Coniferae, Amentiferae, Urticaceae, Cucurbitaceae, and Euphorbiae. All except the first and last of his 15 classes exclusively angiosperms, and it is signficant of his keen perception that, while their sequence has been altered by reshufflings, most of these taxa have been accepted as valid by a majority of systematists for a century and half after de Jussieu. [UKT ¶]

Following publication of this major work, de Jussieu was occupied primarily with the preparation of monographic studies. In addition to these activities he was the founder (in 1793) of one of Europe's great museums, the Musée d'Histoire Naturelle de Paris. In 1826 he resigned his professorship in favor of his son, Adrien de Jussieu.

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DE CANDOLLE 

Three generations of de Candolles  have contributed much to the science of systematic botany. The first important botanist of this great family was Augustin Pyrame de Candolle (1778-1841). He was born in Geneva, Switzerland, and received his botanical training in Paris under Desfontaines. During his lifetime he made many botanical contributions to the fields of physiology, morphology, and taxonomy, but his taxonomic works are the more outstanding. [UKT ¶ ]

His first important botanical work was accomplished soon after arrival in Paris; it consisted of preparing a descriptive text to accompany a series of folio color plates of succulents drawn for L'Héritier (Charles Louis L'Héritier de Brutelle) by the famous botanical artist, Redouté. While still in Paris de Candolle prepared a new and revised edition of Lamarck's Flore francoise. [UKT ¶ ]

From 1808 to 1816 he was Professor of Botany at Montpellier where he published his important Théorie elementaire . . ., wherein he contended that anatomy and not physiology must be the sole basis of classification. [UKT ¶ ]

The last 25 years of his life were spent in Geneva where he continued his monumental work, the Prodromus systematis naturalis regni vegetabilis, in which he proposed to classify and describe every species of seed plant then known to science. This was a stupendous undertaking, and was in reality a species plantarum projected on a more gigantic scale than any [{p030}] previous botanical work. De Condolle himself wrote and produced the first 7 volumes, with the succeeding 10 volumes written by specialists and published after his death under the editorship of his son, Alphonse de Candolle (1806-1893).

As an individual, de Candolle was very much aware of his own importance and greatness. His zeal, industry, and enthusiasm far exceeded that of any of his contemporaries. [UKT ¶ ]

De Candolle proposed a system of classification that was followed in all his taxonomic works. It was a system that was similar in many respects to, and an elaboration of, that of de Jussieu, but retrogresses from the latter in that the ferns were treated as coordinate with the monocots. It has been considered to be superior to the de Jussieu system in that the dicots were subdivided into more basic primary groups of apparent closer affinities. For example, they were divided first into two groups on the basis of presence or absence of corolla, those with corollas subdivided on the basis of gamopetally vs. polypetally, and the latter again divided on the character of ovary position. Aside from these considerations, de Candolle accounted for 161 families of plants as compared with the 100 families known to and recognized by de Jussieu. His importance as a systematist was incerased by the production of his Prodromus, and by his nearly 100 monographs. By the expansion of de Jussieu's system he demonstrated the inadequacy of the Linnaean classification to the extent that the latter could not meet the challenge and by 1840 was superseded. 

During this first half of the nineteenth century there was considerable activity in other parts of Europe in the development of systems of classification, all representing modifications and elaborations of the de Jussieu system. [UKT ¶]

In England, Robert Brown (1773-1858), a contemporary of de Candolle, devised no system of classification, but contributed nonetheless to better understandings of floral morphology and to classification problems. He demonstrated that the gymnosperms were a group apart from the angiosperms and that they were characterized by the presence of naked ovules, and so paved the way for Hofmeister's later formal designations of the two taxa. He was the first to explain the floral morphology and pollination of the Asclepiadaceae, and added much to the knowledge of the Orchidaceae. He demonstrated the nature of the cyathium ['false flowers'] in Euphorbiaceae [exemplified by {rha.saung:}-plants], the morphology and probable derivation of the grass flower, and the floral morphology of the Polygalaceae. Each of these contributions produced a better understanding of the members of these families as concerns their biology and classification.

During the period of 1825 to 1845, no less than 24 systems of classification [{p031}] were proposed. They represented in the main only minor improvements or elaborations over the system of de Jussieu and, aside from the major contributions of de Candolle and of Brown, gave little indication of deep analysis of basic considerations. Many of these modifications represented primarily the adaptations of de Candolle's works onto other languages, accompanied or not by changes in the names given to the higher taxa within the classification. [UKT ¶]

Notable among these are the systems of Endlicher, Brongniart, and Lindley. Endlicher (1805-1849), a Viennese botanist, divided the plant kingdom into the thallophytes (algae, fungi, and lichens) and cormophytes (mosses, ferns, and seed plants). His is a system once widely used in Europe but not adopted by British or American botanists. It is embodied in his Genera plantarum (1836-1840) wherein were treated 6835 genera (6235 were of vascular plants) and was a significant contribution of its time. Brongniart (1770-1847) was a Frenchman who, with considerable foresight, did not consider the taxon often referred to as the Apetalae to be one of closely related elements but distributed the species among those petaliferous families to which they appeared to be more closely related. He called seed plants Phanerogamae and, following Linnaeus, placed all lower groups in the Cryptogamae. [UKT ¶]

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The first publication in English language : John Lindley

In England, John Lindley (1799-1865) proposed a system based on the better features of those of his  predecessors. It was an important revision, not so much for its context and organization as for the fact that it was the first comprehensive natural system to have been published in English and thus made readily available to large numbers of English-speaking peoples. The Lindley system was the first to be accepted widely in Great Britain and America as a successor to that of Linnaeus.

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BENTHAM AND HOOKER.

Bentham and Hooker. The system presented by these two botanists was published as a 3-volume work in Latin, titled Genera plantarum, and was a work that climaxed the period under discussion. [UKT ¶]

George Bentham (1800-1884), an Englishman of moderate independent income, was an amateur but well-trained botanist until almost middle age, after which time he gave the subject of systematic botany all his attention. In addition to being a most critical, discriminating, and analytical systematist he also was an accomplished linguist and Latinist. Prior to his joint publication with Hooker of the Genera plantarum, Bentham published world monographs of the families Labiatae, Ericaceae, Polemoniaceae, Scrophulariaceae, and Polygonaceae. In addition to these he was the author of a 7-volume flora of Australia. [UKT ¶]

Sir Joseph Dalton Hooker (1817-1911), son of the botanist Sir  Wiliam J. Hooker, was [{p032}] more the plant explorer and plant geographer than was Bentham. In addition to botanical research, a considerable part of Hooker's time was devoted to administrative duties associated with the directorship of the Royal Botanical Gardens at Kew. About 1857 Bentham and Hooker agreed to produce jointly a Genera plantarum (1862-1883). This work comprised the names and descriptions of all genera of seed plants then known, classified according to the system proposed by these two botanists. About two-thirds of the contents of the work was written by Bentham, a task requiring a period of nearly 25 years of concentrated effort.

The Bentham and Hooker system was patterned directly on that of de Candolle (a close friend and associate of Bentham), but its text differed from that of the de Candolle system and from any work published by de Candolle, in that every genus was studied anew from material in British and Continental herbaria. Full and complete descriptions were prepared from  studies and dissections of the plants themselves and did not represent a compilation made from existing literature. Almost every large genus was subdivided into subgenera and/or sections, each of which of important species belonging to them. In this work, the category intermediate between  that of class and of order (i.e., the family of contemporary systems) was termed a Cohort, a classificatory unit comparable to the order of more modern systems, and represented a unit of closely related families (the name Cohors was first used by Endlicher for a taxon of higher level). [UKT ¶]

The Genera plantarum was accepted from the first throughout the British Empire and in the United States and was adopted to a lesser extent by some Continental botanists. In this country the  classification remained dominant until shortly before the turn of the present century and is currently retained by many British botanists and in British herbaria.

There was a marked constancy in these systems, from that of de Jussieu to that of Bentham and Hooker. All were predicated on the dogma of the constancy and immutabiilty of species. [UKT ¶]

UKT: The dogma of immutability of the species has been interpreted as compatible with Biblical story of Creation which pre-supposes the existence of a Creator. I far as I know all the religions of the world presupposes the existence of a creator, except Theravada Buddhism of Gautama Buddha. He based his 'teachings' on a set of natural laws, the first of which states that all "All sentient beings are subject to mental suffering". He rejected the idea of a creator as nothing but a figment of imagination. -- UKT121227

True, the later systems were superior to that of de Jussieu, but even the detailed and meticulous work of Bentham and Hooker represented improvements only in degree. Plants were treated by the authors of all these systems as inanimate objects. [UKT ¶]

By way of analogy, it could be said that as the Linnaean system might have grouped all 4-legged articles together (irrespective of whether they were tables, chairs, or commodes) so did the natural systems of this third period group articles of a kind together [{p033}] (as one would group tables, chairs, chests, and commodes -- irrespective of the number of legs each might have). It is interesting to know that the publication of Darwin's theories of evolution and origin of species coincided with the time of production of the first volume of Bentham and Hooker's Genera plantarum and that Hooker then favored a complete reorganization of their classification but was deterred from effecting it by Bentham, who did not then accept the essentials of Darwin's work, although he did do so about a decade later. It was the publication of Wallace's and of Darwin's theories that automatically closed this period in the history of classification systems.

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Period 4. Systems based on phylogeny

( fn033-08).

Period 4 is based on the acceptance of the Theory of Evolution and rejection of the Biblical story of a Creator -- Jehovah God to the Christians and Maha Brahma to the Hindus -- creating the First Man - a story as told by the nomadic tribes of the deserts of the Middle East. My message to Theravada Buddhists of Myanmarpré: Remember, Gautama Buddha had based his 'teachings' on the universal Law of Suffering, not any preconceived idea of as told by some ancient groups of people. -- UKT121227

The rapid spread and acceptance of the theories of Darwin crystallized the dissatisfaction that was associated with the de Candollean system. Sachs was one of the first to abandon the de Candollean system, substituting for it in 1868 a composite system that never was widely accepted. Most of the systems of this fourth period are predicated on the theories of descent and evolution. By these theories, it is now universally accepted by biologists that existing forms of life are the product of evolutionary processes. [UKT ¶]

The classification systems of this period have attempted to classify plants from the simple to the complex (recognizing some seemingly simple conditions to represent reductions from more complex ancestral conditions), and most of these systems have endeavored to establish the genetic and ancestral relationships. The facts that several different systems have been produced, and that a system clearly accounting for the true phylogenetical relationships of plants remains yet to be produced, are evidence that phylogenetic taxonomy of vascular plants is yet in its early stages of progress and will achieve its objectives only as additional facts concerning evolutionary origins and developments of existing plants become known.

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AUGUST WILHELM EICHLER (1839-1887)

August Wilhelm Eichler, in 1875 proposed the rudiments of the first system based on an approach to genetical relationships between plants. This was not a phylogenetic system in the modern sense, but Eichler did accept the concept of evolution. [UKT ¶]

In 1883 he elaborated his earlier treatise into a unified system accounting for all major groups of the entire plant kingdom. It was a system that gradually replaced that of de Candolle in almost all but British and American botanical circles, where the influence of Bentham and Hooker remained dominant. The ultimate widespread acceptance of the basic [{p034}] tenets of Eichler's system makes desirable a familiarity with its significant features.

Eichler divided the plant kingdom into two subgroups: Cryptogamae and Phanerogmae. The latter contained the seed plants and the former the ferns, bryophytes, hepatics, fungi, and algae. The Cryptogamae were separated into three divisions: Thallophytes, Bryophytes, and Pteriodophytes. Eichler treated the Algae as separate from the Fungi and divided the former into the four well-known groups of Cyanophyceae, Chlorophyceae, Phaeophyceae, and Rhodophyceae. The bryophytes were divided into two classes, the Hepaticae and Musci, while the pteridophytes were separated into three classes, Equisetineae, Lycopodineae, and Filicineae. [UKT ¶]

The seed plants (Phanerogamae) were divided for the first time into the two major taxa of Angiospermae and Gymnospermae with the former composed of two classes, the Monocotyledoneae and the Dicotyledoneae. Eichler's classification of the Phanerogamae was predicated on the premise that plants in their evolutional development; or, as expressed by Hutchinson (1948) ". . . plants without petals . . . were usually regarded as representing a more primitive type than those with well-developed petals . . . " Eichler did not consider tenable the data then available to him (and that later served the basis of an opposing premise), that some of the so-called higher plants (as Typha, the cattail) might be simple by the loss or reduction of ancestral structures, a premise whose adoption would have altered materially his alignment of major groups of plants.

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ADOLPH ENGLER (1844-1930)

Adolph Engler, in 1892 published, as part of a guide to the plants in the Breslau botanic garden, a classification that was based on that of Eichler, and which was so well publicized as to be adopted by a majority of botanists of the world soon after the turn of the present century. [UKT ¶]

Engler's system differed from that of Eichler more in matters of detail and in the nomenclature of major categories than in the basic philosophy or fundamental concepts on which the categories were established. Many of Engler's modifications of Eichler's system show the influence of earlier proposals of Braun, of Brongniar, and of Sachs. [UKT ¶]

The seed plants (termed Embryophyta Siphonogama by Engler) were divided into Gymnospermae and Angiospermae, the latter into two classes, Monocotyledoneae and Dicotyledoneae and the dicots into the subclasses Archychlamideae (composed of the Choripetalae with separate petals, and Apetalae without petals) and Metachlamydeae (the corolla gamopetalous petals united). By this system each subclass is subdivided [{p035}] into orders and they are composed of presumably related families. In their accounting of the principles for a systematic arrangement of the angiosperms, Engler and Diels (1936) listed conditions accepted as primitive and contrasted each with the presumed derived condition. [UKT ¶]

Among the objectionable features was the acceptance by Engler of the dichlamydeous flowers ( perianth of two series, as calyx and corolla) as derived from monochlamydeous flowers (perianth of a single series or whorl), the derivation of all parietal placentation from parietal, and the interpretation of the majority of simple unisexual flowers as primitive.

One reason for the widespread adoption of the Engler system by botanists was that Engler and his associate, Prantl, applied their system to the plants of the world and by their 20-volume work, Die natürlichen Pflanzenfamillien (1887-1899), provided a means for the identification of all of the known genera of plants from algae to the most advanced seed plants. This was an illustrated work, with modern keys, and was responsible perhaps more than anything else for "putting across" the system. [UKT ¶]

A second and much more detailed edition of this work, under the successive editorships of several outstanding German systematists (Engler, Engelmann, Diels, et al.) was begun in Berlin in 1924. Only minor modifications and changes were effected in his system, primarily in Engler and Gilg's (and later by Engler and Diels) Syllabus der Pflanzenfamilien, a one-volume work published in many editions that gave their arrangement of the classes, orders, and families of plants. The latest and eleventh edition of his work was published in 1936.

Engler considered the monocots to be more primitive than the dicots, the orchids more highly developed than the grasses and, among the dicots the so-called Amentiferae (willows, birches, oaks, and walnuts) together with other families whose flowers are devoid of perianth, to represent primitive types from which petaliferous elements were evolved. [UKT ¶]

These views are not currently accepted in toto by many schools of taxonomic thought. The current dominance of the Engler system in many areas is due largely to the impetus given it by the detailed, far-reaching, all-embracive influence of Engler's many publications. In addition to those mentioned above, these include encyclopedic works written by leading German taxonomists under Engler's editorship.

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RICHARD VON WETTSTEIN (1862-1931),

Richard von Wettstein, an Austrian botanist, published in 1901 Handbuch der systematise Botanik and in the posthumous 2-volume fourth edition (1930-1935) presented his latest views [{p036}] on the phylogeny of plants. While patterning the basic structures of his system somewhat along that of Engler's, Wettstein rearranged the relative positions of many dicot families and presented views concurred with by most contemporary phylogenists. In general his system was a much better phylogenetic classification than was Engler's. (See Chapter 6 for explanation and analysis.)

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CHARLES E. BESSEY (1845-1915),

Charles E. Bessey, a student of Asa Gray and long established at the University of Nebraska, was the first American to make a major contribution to the knowledge of plant relationships and classification and the first to represent a classification to be truly phylogenetic. He did not accept the Eichler-Engler hypotheses. In his early years as a botanist he was considerably influenced by the upheaval in scientific thought occasioned by the argumentative subject of species origin and evolution as propounded by both Wallace and Darwin. In general, Bessey's was the system of Bentham and Hooker realigned according to evolutionary principles, with the cohorts of the latter called orders, and in most cases each was accompanied by new names, and the orders were retermed families. After several revisions, Bessey's system appeared in its last form in 1915 with the orders and families arranged as indicated in Chapter 6.

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HANS HALLIER (1868-1932)

Hans Hallier, published a phologenetic classification that was based on many of the same phyletic principles as that by Bessey. It differed primarily in his having taken greater cognizance of the then current researches in paleobotany, anatomy, serology, and ontogeny than had Bessey and was more of a synthesis of recent (and frequently untested) findings than other contemporary classifications. Hallier rejected Engler's concept of the primitive flower, adopting instead, as did Bessey, the strobiloid type of flower. His treatment of the monocots may be less critical than that of the dicots, and his classification, despite innumerable examples of his keen perception scattered throughout it, is not in accord with recent finding to nearly the extent of Bessey classifications. (See Chapter 6 for full discussion.)

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JOHN HUTCHINSON (1884-1972)

UKT: Death of Hutchinson in 1972 from: http://www.kew.org/heritage/people/hutchinson.html 121228

John Hutchinson, formerly of the Royal Botanic Garden, Kew, England, and a leading contemporary exponent of a phylogenetic system of classification, has concerned himself primarily with the angiosperms, publishing his classification of them in a 2-volume work, The families of flowering plants (1926, 1934) and as revised in his British flowering plants (1948). Hutchinson's classification has closer affinities with those of Bentham and Hooker and of Bessey than with that of [{p037}] Engler, but differs from any of these by several fundamental theses. In his latest revision (1948) Hutchinson outlined the principles of classification adopted by him (see Chapter 6).

The system of Hutchinson is the most recent to be presented in appreciable detail, but to date this detail has been accorded only to the seed-bearing plants and of them primarily to the angiosperms. He has published no recent conclusions on the phylogenies within the gymnosperms and none at all concerning groups below the seed plants. Many taxonomists await Hutchinson's amplification and discussion, substantiated by references to factual data, of his principles of phylogeny. Many also await his presentation of reasons accounting for his classification of taxa in the categories of family and above.

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Other contemporary systems

(fn037-09)

Numerous other phyolgenists have devised and proposed systems of classification other than those discussed above. Notable among them are the systems proposed by Rendle, by Mez, and by Tippo.

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ALFRED BARTON RENDLE (1865-1938),

Alfred Barton Rendle, Keeper of the Department of Botany, British Museum of Natural History, London, from 1906 to 1930, is known not only for his studies of the Gramineae, Orchidaceae, and Naiadaceae, for his leadership associated with international nomenclatural legislation, but also for his 2-volume Classification of flowering plants (1904,1925). The revision of the first volume was published in 1930. Rendle's system, basically that of Engler and Prantl, is one of convenience rather than one of modern phylogenetic significance. It treats the amentiferous and apetalous plants as among the primitive dicots, places the grasses subordinate to lilies, and does not accept the phylogenetic considerations that treat the Ranales as primitive to other dicots (for details, see Chapter 6).

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KARL CHRISTIAN MEZ (1866-1944),

Karl Christian Mez, Professor of Botany, University of Koenigsberg, Germany, presented a paper in 1926 (revised and amplified in 1936) recounting his theory that relationships between the larger groups of genetically related plants could be determined by study and analysis of their protein reactions. [UKT ¶]

This physiological approach, sometimes known as the serum diagnosis, consisted of mixing an extracted plant protein with serum, either in animal or in vitro and, following the formation of antibodies in the inoculated serum, of adding a protein ( fn037-10) [{p038}] extract prepared from the plant whose relationship is being studied. If a precipitation occurred when this second protein extract was added to the serum, a genetical relationship was believed to be indicated to exist between the plants involved. The proximity of the relationship was considered to be indicated by the abundance and character of the precipitate and the degree of dilution of the serum and extract at which precipitation would occur. The relationships indicated by this technique concurred to a degree with those proposed by Bessey and by Hutchinson. The utilization of data derived from serum diagnoses may contribute important corroboratory evidence to the formation of an ultimate system of classification.

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OSWALD TIPPO   (1912-1999)

UKT: Birth and death of Oswald Tippo from:
http://www.nytimes.com/1999/06/19/us/oswald-tippo-_.html 121228

Oswald Tippo, of the University of Illinois, published an outline (1942) of a projected classification based on ". . . the newest, sound developments in all the branches of plant phylogeny and in which the various groups are named in such a way as to indicate rank or degree of affinity and in which the various group names are brought into conformity with the classificatory system used by zoologists" (see Fig. 17). The system was not developed by Tippo, who "claims no great degree of originality for his classification for it is a compilation, a synthesis of several proposals." The classification of the nonvascular plants followed that of Smith (1938) and the basic arrangement of vascular plants followed that proposed by Eames (1936). The concepts and indicated relationships were in part the result of greater recognition and synthesis of paleobotanical data than are reflected in other phylogenetic systems. This emphasized the dependence on vegetative characters such as plant form, branching, and vascular anatomy in arriving at the natural groupings of the larger categories.

The Engler system remains dominant in the great herbaria of this country, but largely because it is the latest to account in detail for the entire plant kingdom. The more nearly phylogentic systems of Bessey, of Hutchinson, and of Tippo are thought to be more accurate in their arrangement and more sound in the tenets on which they are founded, but - as pointed out in the Preface to this text - no one of them has been applied to the world flora (even of vascular plants) to a degree comparable with that of the Engler system. The student should recognize that the Pteridophyta themselves are not a homogeneous group bound by any one or two sets of characters; that there is no distinct line of demarcation between gymnosperms and angiosperms, or between monocotyledons and dicotyledons; and that a truly phylogenetic classification will be reticulate in character and will not lend itself to listing taxa in [{p030}] straight lines. Tippo's skeleton outline clearly indicates the probable major groupings to be expected in the system of the near future.

This review of the systems of classification demonstrates that taxonomic efforts devoted to the development of a more nearly perfect classification of plants have followed in the wake of those men whose interests have shifted from generalization to interests of specialization. Linnaeus, the greatest cataloguer and classifier of all time, was not only a systematist but a capable naturalist, a biological investigator, and a practicing physician of note; A. P. de Candolle was a physiologist, and a nomenclaturist, as well as a producer of extensive monographs; Engler was as much a plant geographer and botanical administrator as he was a taxonomist; Bessey, doubtless of necessity, devoted more efforts to teaching than to phylogenetic studies; much of the recent work of Hutchinson, aside from his studies on the flora of west tropical Africa, has been directed toward phylogenetic studies. It is probable that the phylogenist of the future will be so concerned with his own efforts as to have little concern for the identity of plants per se. The average taxonomic botanist is concerned today more with studies associated with floristics and monography of minor units (families and genera and their components) than he is with coping with the fundamental problems of phylogeny of major taxa. Underlying causes for these changes are indicated in Chapter 5. Chronology forces the premature closing of the treatment of this last and current period of systems of plant classification. The period has not ended. Research in the fields of paleobotany, comparative anatomy, serology, cytogenetics, and morphology continues and, with the accumulation and synthesis of data from these and other interrelated branches of botanical science, a new and more nearly perfect system of classification will be evolved.

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Footnotes:

fn027-07 Early botanists, following Linnaeus, designated as Classis (Class) the category now known as an order, and as Ordo (Order) that now known as a family. While there were some exceptions (by Adanson, de Candolle), this usage of class and order prevailed until the beginning of the twentieth century.
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fn033-08 See Chapter 6 for explanation and analysis of current systems of classification.
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fn037-09 See Chapter 6 for an accounting of additional contemporary systems, including those of Pulle, Skottsberg, et al.
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fn037-10 : See Chapter 6 for an accounting of additional contemporary systems, including those by Pulle, Skottsberg, et al.
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UKT notes:

cyathium

From Wikipedia: http://en.wikipedia.org/wiki/Cyathium
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A cyathium (plural: cyathia) is one of the specialised pseudanthia ("false flowers") forming the inflorescence of plants in the genus Euphorbia (Euphorbiaceae).

-- UKT: The Euphobia are represented in Myanmarpré by {rha.saung:}-plants.
See: Botanical Names of Myanmar Plants of Importance, by Agri. Dept. (Planning), Govt. Union of Myanmar, 2000, entries 52-1370 to 1378, etc.

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perianth

perianth n. 1. The outer envelope of a flower, consisting of either the calyx or the corolla, or both. [French périanthe from New Latin perianthum Greek peri- peri-Greek anthos flower] -- AHTD

Perianth. The perianth is an accessory part of the flower more or less enveloping the organs of reproduction, and is classically treated as composed of an outer cycle or whorl (the calyx) and an inner cycle or whorl (the corolla). -- Lawrence p066

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