History of plant systematics
Encyclopedia
The history of plant systematics—the biological classification
Biological classification
Biological classification, or scientific classification in biology, is a method to group and categorize organisms by biological type, such as genus or species. Biological classification is part of scientific taxonomy....

 of plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

s—stretches from the work of ancient Greek to modern evolutionary biologists. As a field of science, plant systematics came into being only slowly, early plant lore usually being treated as part of the study of medicine. Later, classification and description was driven by natural history
Natural history
Natural history is the scientific research of plants or animals, leaning more towards observational rather than experimental methods of study, and encompasses more research published in magazines than in academic journals. Grouped among the natural sciences, natural history is the systematic study...

 and natural theology
Natural theology
Natural theology is a branch of theology based on reason and ordinary experience. Thus it is distinguished from revealed theology which is based on scripture and religious experiences of various kinds; and also from transcendental theology, theology from a priori reasoning.Marcus Terentius Varro ...

. Until the advent of the theory of evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

, nearly all classification was based on the scala naturae. The professionalization of botany in the 18th and 19th century marked a shift toward more holistic classification methods, eventually based on evolutionary relationships.

Antiquity

Historians of botany trace the origins of botanical classification with folk taxonomy
Folk taxonomy
A folk taxonomy is a vernacular naming system, and can be contrasted with scientific taxonomy. Folk biological classification is the way peoples describe and organize their natural surroundings/the world around them, typically making generous use of form taxa like "shrubs", "bugs", "ducks",...

 and ancient Greece
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

.

Theophrastus
Theophrastus
Theophrastus , a Greek native of Eresos in Lesbos, was the successor to Aristotle in the Peripatetic school. He came to Athens at a young age, and initially studied in Plato's school. After Plato's death he attached himself to Aristotle. Aristotle bequeathed to Theophrastus his writings, and...

’s (372–287 BC), a student of Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...

, produced Historia Plantarum
Historia Plantarum
Historia Plantarum is Latin and literally means History of Plants, although in reality it means something closer to "on plants" or "treatise on plants". There has been more than one book by this title....

, the earliest surviving treatise on plants, where he listed the names of over 500 plant species. However he did not articulate a formal classification scheme; instead he relied on the common groupings of folklore combined with growth form: tree shrub; undershrub; or herb.

The Materia medica
Materia medica
Materia medica is a Latin medical term for the body of collected knowledge about the therapeutic properties of any substance used for healing . The term 'materia medica' derived from the title of a work by the Ancient Greek physician Pedanius Dioscorides in the 1st century AD, De materia medica libre...

of Dioscorides was also an important early compendium of plant descriptions (over five hundred); it was in use from its publication in the 1st century until the 16th century.

Early modern period

In the 16th century, works by Otto Brunfels
Otto Brunfels
Otto Brunfels was a German theologian and botanist...

, Hieronymus Bock
Hieronymus Bock
Hieronymus Bock was a German botanist, physician, and Lutheran minister who began the transition from medieval botany to the modern scientific worldview by arranging plants by their relation or resemblance....

, and Leonhart Fuchs
Leonhart Fuchs
Leonhart Fuchs , sometimes spelled Leonhard Fuchs, was a German physician and one of the three founding fathers of botany, along with Otto Brunfels and Hieronymus Bock .-Biography:...

 helped to revive interest in natural history based on first-hand observation; Bock in particular included environmental and life cycle information in his descriptions. With the influx of exotic species in the Age of Exploration, the number of known species expanded rapidly, but most authors were far more interested in the medicinal properties of individual plants than an overarching classification system. Later influential Renaissance books include those of Caspar Bauhin and Andrea Cesalpino
Andrea Cesalpino
Andrea Cesalpino was an Italian physician, philosopher and botanist....

. Bauhin described over 6000 plants, which he arranged into 12 books and 72 sections based on a wide range of common characteristics. Cesalpino based his system on the structure of the organs of fructification, using the Aristotelian technique of logical division
Arbor porphyriana
An arbor porphyriana or Porphyrian tree, created by Porphyry, is a hierarchical ontology, construction in logic consisting of three rows or columns of words; the middlemost whereof contains the series of genus and species, and bears some analogy to the trunk...

.

In the late 17th century, the most influential classification schemes were those of English botanist and natural theologian John Ray
John Ray
John Ray was an English naturalist, sometimes referred to as the father of English natural history. Until 1670, he wrote his name as John Wray. From then on, he used 'Ray', after "having ascertained that such had been the practice of his family before him".He published important works on botany,...

 and French botanist Joseph Pitton de Tournefort
Joseph Pitton de Tournefort
Joseph Pitton de Tournefort was a French botanist, notable as the first to make a clear definition of the concept of genus for plants.- Biography :...

. Ray, who listed over 18,000 plant species in his works, is credited with establishing the monocot/dicot division and some of his groups — mustards
Brassicaceae
Brassicaceae, a medium sized and economically important family of flowering plants , are informally known as the mustards, mustard flowers, the crucifers or the cabbage family....

, mints
Lamiaceae
The mints, taxonomically known as Lamiaceae or Labiatae, are a family of flowering plants. They have traditionally been considered closely related to Verbenaceae, but in the 1990s, phylogenetic studies suggested that many genera classified in Verbenaceae belong instead in Lamiaceae...

, legumes
Fabaceae
The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...

 and grasses
Poaceae
The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...

 — stand today (though under modern family names). Tournefort used an artificial system based on logical division which was widely adopted in France and elsewhere in Europe up until Linnaeus.

The book that had an enormous accelerating effect on the science of plant systematics was Species Plantarum
Species Plantarum
Species Plantarum was first published in 1753, as a two-volume work by Carl Linnaeus. Its prime importance is perhaps that it is the primary starting point of plant nomenclature as it exists today. This means that the first names to be considered validly published in botany are those that appear...

(1753) by Linnaeus
Carolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...

. It presented a complete list of the plant species then known to Europe, ordered for the purpose of easy identification using the number and arrangement of the male and female sexual organs of the plants. Of the groups in this book, the highest rank that continues to be used today is the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

. The consistent use of binomial nomenclature
Binomial nomenclature
Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...

 along with a complete listing of all plants provided a huge stimulus for the field.

Although meticulous, the classification of Linnaeus served merely as an identification manual; it was based on phenetics
Phenetics
In biology, phenetics, also known as taximetrics, is an attempt to classify organisms based on overall similarity, usually in morphology or other observable traits, regardless of their phylogeny or evolutionary relation. It is closely related to numerical taxonomy which is concerned with the use of...

 and did not regard evolutionary relationships among species. It assumed that plant species were given by God and that what remained for humans was to recognise them and use them (a Christian reformulation of the scala naturae or Great Chain of Being). Linnaeus was quite aware that the arrangement of species in the Species Plantarum was not a natural system, i.e. did not express relationships. However he did present some ideas of plant relationships elsewhere.

Modern and Contemporary periods

Significant contributions to plant classification came from de Jussieu
De Jussieu system
An early attempt at a system of plant taxonomy, the de Jussieu System recognises as the main groups:*I. Acotyledones*::Classes: 1, with as families: Fungi, Algae, Hepaticae, Musci, Filices, Najades*II. Monocotyledones...

 (inspired by the work of Adanson) in 1789 and the early nineteenth century saw the start of work by de Candolle, culminating in the Prodromus.

A major influence on plant systematics was the theory of evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

 (Charles Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...

 published Origin of Species in 1859), resulting in the aim to group plants by their phylogenetic relationships. To this was added the interest in plant anatomy
Plant anatomy
Plant anatomy or phytotomy is the general term for the study of the internal structure of plants. While originally it included plant morphology, which is the description of the physical form and external structure of plants, since the mid-20th century the investigations of plant anatomy are...

, aided by the use of the light microscope and the rise of chemistry, allowing the analysis of secondary metabolites.

Currently, the strict use of epithets in botany, although regulated by international codes, is considered unpractical and outdated. The very notion of species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

, the fundamental classification unit, is often up to subjective intuition and thus can not be well defined. As a result, estimate of the total number of existing "species" (ranging from 2 million to 100 million) becomes a matter of preference.

While scientists have agreed for some time that a functional and objective classification system must reflect actual evolutionary processes and genetic relationships, the technological means for creating such a system did not exist until recently. In the 1990s DNA technology saw immense progress, resulting in unprecedented accumulation of DNA sequence data
DNA sequencing
DNA sequencing includes several methods and technologies that are used for determining the order of the nucleotide bases—adenine, guanine, cytosine, and thymine—in a molecule of DNA....

 from various genes present in compartments of plant cells. In 1998 a ground-breaking classification of the angiosperms (the APG system
APG system
The APG system of plant classification is the first, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in 1998 by the Angiosperm Phylogeny Group. It was superseded in 2003 by a revision, the APG II system, and then in 2009 by a further...

) consolidated molecular phylogenetics (and especially cladistics
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...

 or phylogenetic systematics) as the best available method. For the first time relatedness could be measured in real terms, namely similarity of the molecules comprising the genetic code.

Timeline of publications

  • [available online at Gallica
    [available online at Gallica
    [available online at Gallica
    [available online at Gallica
    [available online at Gallica
    [In English, with list of systems since 1703 (John Ray) until 1845; available online at Gallica

See also

  • List of systems of plant taxonomy
  • Centro de Estudos e Pesquisas Ambientais
    Centro de Estudos e Pesquisas Ambientais
    CEPA is a center of environmental studies, situated in São Francisco do Sul and in São Bento in the state of Santa Catarina, Brazil. It is part of the University of Joinville - UNIVILLE and harbours scientists studying the ecology of the Mata atlântica, the Brazilian Atlantic rain forest as well as...

  • Conservation movement
    Conservation movement
    The conservation movement, also known as nature conservation, is a political, environmental and a social movement that seeks to protect natural resources including animal, fungus and plant species as well as their habitat for the future....

  • Environmental protection
    Environmental protection
    Environmental protection is a practice of protecting the environment, on individual, organizational or governmental level, for the benefit of the natural environment and humans. Due to the pressures of population and our technology the biophysical environment is being degraded, sometimes permanently...

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