The history of plant systematics—the

biological classification In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are give ...

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...

s—stretches from the work of ancient Greek to modern

evolutionary biologists Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life f ...

. 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 and natural theology. Until the advent of the theory of evolution, 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

The peripatetic philosopher

Theophrastus Theophrastus (; grc-gre, Θεόφραστος ; c. 371c. 287 BC), a Greek philosopher and the successor to Aristotle in the Peripatetic school. He was a native of Eresos in Lesbos.Gavin Hardy and Laurence Totelin, ''Ancient Botany'', Routle ...

(372–287 BC), as a student of

Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of ph ...

Ancient Greece Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean Sea, Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of Classical Antiquity, classical antiquity ( AD 600), th ...

, wrote '' Historia Plantarum'', the earliest surviving treatise on plants, where he listed the names of over 500 plant species.''Concise Encyclopedia Of Science And Technology'', McGraw-Hill He did not articulate a formal classification scheme, but relied on the common groupings of

folk taxonomy A folk taxonomy is a vernacular naming system, as distinct from scientific taxonomy. Folk biological classification is the way people traditionally describe and organize their natural surroundings/the world around them, typically making generou ...

combined with growth form: tree shrub; undershrub; or herb. The ''

De Materia Medica (Latin name for the Greek work , , both meaning "On Medical Material") is a pharmacopoeia of medicinal plants and the medicines that can be obtained from them. The five-volume work was written between 50 and 70 CE by Pedanius Dioscorides, ...

'' of

Dioscorides Pedanius Dioscorides ( grc-gre, Πεδάνιος Διοσκουρίδης, ; 40–90 AD), “the father of pharmacognosy”, was a Greek physician, pharmacologist, botanist, and author of '' De materia medica'' (, On Medical Material) —a 5-vo ...

was an important early compendium of plant descriptions (over five hundred), classifying plants chiefly by their medicinal effects.

Medieval

The

Byzantine The Byzantine Empire, also referred to as the Eastern Roman Empire or Byzantium, was the continuation of the Roman Empire primarily in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinopl ...

emperor Constantine VII sent a copy of

' pharmacopeia to the

Umayyad The Umayyad Caliphate (661–750 CE; , ; ar, ٱلْخِلَافَة ٱلْأُمَوِيَّة, al-Khilāfah al-ʾUmawīyah) was the second of the four major caliphates established after the death of Muhammad. The caliphate was ruled by the ...

Caliph

Abd al-Rahman III ʿAbd al-Rahmān ibn Muḥammad ibn ʿAbd Allāh ibn Muḥammad ibn ʿAbd al-Raḥmān ibn al-Ḥakam al-Rabdī ibn Hishām ibn ʿAbd al-Raḥmān al-Dākhil () or ʿAbd al-Rahmān III (890 - 961), was the Umayyad Emir of Córdoba from 912 to 92 ...

who ruled Córdoba in the 9th century, and also sent a monk named Nicolas to translate the book into Arabic. It was in use from its publication in the 1st century until the 16th century, making it one of the major

herbal A herbal is a book containing the names and descriptions of plants, usually with information on their medicinal, tonic, culinary, toxic, hallucinatory, aromatic, or magical powers, and the legends associated with them.Arber, p. 14. A herbal m ...

s throughout the Middle Ages. The

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

criteria of medieval texts is different from what is used today. Plants with similar external appearance were usually grouped under the same species name, though in modern taxonomy they are considered different.Middle East Garden Traditions: Unity and Diversity : Questions, Methods and Resources in a Multicultural Perspective Volume 31
/ref> Abū l-Khayr's botanical work''Umdat al-tabib fi ma'rifat al-n abat (Medical support for the knowledge of plants by all experts)'' is the most complete Andalusi botanical text known to modern scholars. It is noted for its detailed descriptions of

plant morphology Phytomorphology is the study of the physical form and external structure of plants.Raven, P. H., R. F. Evert, & S. E. Eichhorn. ''Biology of Plants'', 7th ed., page 9. (New York: W. H. Freeman, 2005). . This is usually considered distinct from ...

and phenology.

Early modern period

In the 16th century, works by

Otto Brunfels Otto Brunfels (also known as Brunsfels or Braunfels) (believed to be born in 1488 – 23 November 1534) was a German theologian and botanist. Carl von Linné listed him among the "Fathers of Botany". Life After studying theology and philosophy ...

Hieronymus Bock Hieronymus Bock ( Latinised Hieronymus Tragus; c. 1498 – 21 February 1554) 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 re ...

, and Leonhart Fuchs 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 Age of Discovery (or the Age of Exploration), also known as the early modern period, was a period largely overlapping with the Age of Sail, approximately from the 15th century to the 17th century in European history, during which seafari ...

, 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 ( Latinized as Andreas Cæsalpinus) (6 June 1524 – 23 February 1603) was a Florentine physician, philosopher and botanist. In his works he classified plants according to their fruits and seeds, rather than alphabetically ...

. 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. In the late 17th century, the most influential classification schemes were those of English botanist and natural theologian John Ray and French botanist

Joseph Pitton de Tournefort Joseph Pitton de Tournefort (5 June 165628 December 1708) was a French botanist, notable as the first to make a clear definition of the concept of genus for plants. Botanist Charles Plumier was his pupil and accompanied him on his voyages. Lif ...

. Ray, who listed over 18,000 plant species in his works, is credited with establishing the

monocot Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one Embryo#Plant embryos, embryonic leaf, or cotyledon. Th ...

dicot The dicotyledons, also known as dicots (or, more rarely, dicotyls), are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, t ...

division and some of his groups — mustards,

mints A mint or breath mint is a food item often consumed as an after-meal refreshment or before business and social engagements to improve breath odor. Mints are commonly believed to soothe the stomach given their association with natural byproducts ...

, legumes and

grasses Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns ...

— 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'' (1753) by

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

. 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 ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

. The consistent use of

binomial nomenclature In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

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 In biology, phenetics ( el, phainein – to appear) , 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 re ...

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, the name of a French family which came into prominence towards the close of the sixteenth century, and was known for a century and a half for the botanists it produced. The following are its more eminent members: *Antoine de Jussieu (1 ...

(inspired by the work of

Michel Adanson Michel Adanson (7 April 17273 August 1806) was an 18th-century French botanist and naturalist who traveled to Senegal to study flora and fauna. He proposed a "natural system" of taxonomy distinct from the binomial system forwarded by Linnaeus. ...

) 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 is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

(

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended ...

published ''

Origin of Species ''On the Origin of Species'' (or, more completely, ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life''),The book's full original title was ''On the Origin of Species by Me ...

'' in 1859), resulting in the aim to group plants by their

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

relationships. To this was added the interest in

plant anatomy Plant anatomy or phytotomy is the general term for the study of the internal structure of plants. Originally it included plant morphology, the description of the physical form and external structure of plants, but since the mid-20th century plant ...

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

secondary metabolites Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the nor ...

. Currently, the strict use of

epithets An epithet (, ), also byname, is a descriptive term (word or phrase) known for accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, di ...

in botany, although regulated by international codes, is considered unpractical and outdated. The very notion of

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, 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 from various genes present in compartments of plant cells. In 1998 a ground-breaking classification of the angiosperms (the

APG system The APG system (Angiosperm Phylogeny Group system) of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved A ...

) consolidated

molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

(and especially

cladistics Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived cha ...

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

* * * * * * * * * (In English, with list of systems since 1703 (John Ray) until 1845)

References

{{DEFAULTSORT:History Of Plant Systematics Plant taxonomy History of botany