Botany

Image of ripe nutmeg fruit split open to show red aril
The fruit of Myristica fragrans, a species native to Indonesia, is the source of two valuable spices, the red aril (mace) enclosing the dark brown nutmeg.

Botany, also called plant science(s), plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek word βοτάνη (botanē) meaning "pasture", "grass", or "fodder"; βοτάνη is in turn derived from βόσκειν (boskein), "to feed" or "to graze".[1][2][3] Traditionally, botany has also included the study of fungi and algae by mycologists and phycologists respectively, with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress. Nowadays, botanists (in the strict sense) study approximately 410,000 species of land plants of which some 391,000 species are vascular plants (including ca 369,000 species of flowering plants),[4] and ca 20,000 are bryophytes.[5]

Botany originated in prehistory as herbalism with the efforts of early humans to identify – and later cultivate – edible, medicinal and poisonous plants, making it one of the oldest branches of science. Medieval physic gardens, often attached to monasteries, contained plants of medical importance. They were forerunners of the first botanical gardens attached to universities, founded from the 1540s onwards. One of the earliest was the Padua botanical garden. These gardens facilitated the academic study of plants. Efforts to catalogue and describe their collections were the beginnings of plant taxonomy, and led in 1753 to the binomial system of Carl Linnaeus that remains in use to this day.

In the 19th and 20th centuries, new techniques were developed for the study of plants, including methods of optical microscopy and live cell imaging, electron microscopy, analysis of chromosome number, plant chemistry and the structure and function of enzymes and other proteins. In the last two decades of the 20th century, botanists exploited the techniques of molecular genetic analysis, including genomics and proteomics and DNA sequences to classify plants more accurately.

Modern botany is a broad, multidisciplinary subject with inputs from most other areas of science and technology. Research topics include the study of plant structure, growth and differentiation, reproduction, biochemistry and primary metabolism, chemical products, development, diseases, evolutionary relationships, systematics, and plant taxonomy. Dominant themes in 21st century plant science are molecular genetics and epigenetics, which are the mechanisms and control of gene expression during differentiation of plant cells and tissues. Botanical research has diverse applications in providing staple foods, materials such as timber, oil, rubber, fibre and drugs, in modern horticulture, agriculture and forestry, plant propagation, breeding and genetic modification, in the synthesis of chemicals and raw materials for construction and energy production, in environmental management, and the maintenance of biodiversity.

History

Early botany

engraving of cork cells from Hooke's Micrographia, 1665
An engraving of the cells of cork, from Robert Hooke's Micrographia, 1665

Botany originated as herbalism, the study and use of plants for their medicinal properties.[6] Many records of the Holocene period date early botanical knowledge as far back as 10,000 years ago.[7] This early unrecorded knowledge of plants was discovered in ancient sites of human occupation within Tennessee, which make up much of the Cherokee land today.[7] The early recorded history of botany includes many ancient writings and plant classifications. Examples of early botanical works have been found in ancient texts from India dating back to before 1100 BC,[8][9] in archaic Avestan writings, and in works from China before it was unified in 221 BC.[8][10]

Modern botany traces its roots back to Ancient Greece specifically to Theophrastus (c. 371–287 BC), a student of Aristotle who invented and described many of its principles and is widely regarded in the scientific community as the "Father of Botany".[11] His major works, Enquiry into Plants and On the Causes of Plants, constitute the most important contributions to botanical science until the Middle Ages, almost seventeen centuries later.[11][12]

Another work from Ancient Greece that made an early impact on botany is De Materia Medica, a five-volume encyclopedia about herbal medicine written in the middle of the first century by Greek physician and pharmacologist Pedanius Dioscorides. De Materia Medica was widely read for more than 1,500 years.[13] Important contributions from the medieval Muslim world include Ibn Wahshiyya's Nabatean Agriculture, Abū Ḥanīfa Dīnawarī's (828–896) the Book of Plants, and Ibn Bassal's The Classification of Soils. In the early 13th century, Abu al-Abbas al-Nabati, and Ibn al-Baitar (d. 1248) wrote on botany in a systematic and scientific manner.[14][15][16]

In the mid-16th century, "botanical gardens" were founded in a number of Italian universities – the Padua botanical garden in 1545 is usually considered to be the first which is still in its original location. These gardens continued the practical value of earlier "physic gardens", often associated with monasteries, in which plants were cultivated for medical use. They supported the growth of botany as an academic subject. Lectures were given about the plants grown in the gardens and their medical uses demonstrated. Botanical gardens came much later to northern Europe; the first in England was the University of Oxford Botanic Garden in 1621. Throughout this period, botany remained firmly subordinate to medicine.[17]

German physician Leonhart Fuchs (1501–1566) was one of "the three German fathers of botany", along with theologian Otto Brunfels (1489–1534) and physician Hieronymus Bock (1498–1554) (also called Hieronymus Tragus).[18][19] Fuchs and Brunfels broke away from the tradition of copying earlier works to make original observations of their own. Bock created his own system of plant classification.

Physician Valerius Cordus (1515–1544) authored a botanically and pharmacologically important herbal Historia Plantarum in 1544 and a pharmacopoeia of lasting importance, the Dispensatorium in 1546.[20] Naturalist Conrad von Gesner (1516–1565) and herbalist John Gerard (1545–c. 1611) published herbals covering the medicinal uses of plants. Naturalist Ulisse Aldrovandi (1522–1605) was considered the father of natural history, which included the study of plants. In 1665, using an early microscope, Polymath Robert Hooke discovered cells, a term he coined, in cork, and a short time later in living plant tissue.[21]

Early modern botany

Photograph of a garden
The Linnaean Garden of Linnaeus' residence in Uppsala, Sweden, was planted according to his Systema sexuale.

During the 18th century, systems of plant identification were developed comparable to dichotomous keys, where unidentified plants are placed into taxonomic groups (e.g. family, genus and species) by making a series of choices between pairs of characters. The choice and sequence of the characters may be artificial in keys designed purely for identification (diagnostic keys) or more closely related to the natural or phyletic order of the taxa in synoptic keys.[22] By the 18th century, new plants for study were arriving in Europe in increasing numbers from newly discovered countries and the European colonies worldwide. In 1753 Carl von Linné (Carl Linnaeus) published his Species Plantarum, a hierarchical classification of plant species that remains the reference point for modern botanical nomenclature. This established a standardised binomial or two-part naming scheme where the first name represented the genus and the second identified the species within the genus.[23] For the purposes of identification, Linnaeus's Systema Sexuale classified plants into 24 groups according to the number of their male sexual organs. The 24th group, Cryptogamia, included all plants with concealed reproductive parts, mosses, liverworts, ferns, algae and fungi.[24]

Increasing knowledge of plant anatomy, morphology and life cycles led to the realisation that there were more natural affinities between plants than the artificial sexual system of Linnaeus. Adanson (1763), de Jussieu (1789), and Candolle (1819) all proposed various alternative natural systems of classification that grouped plants using a wider range of shared characters and were widely followed. The Candollean system reflected his ideas of the progression of morphological complexity and the later classification by Bentham and Hooker, which was influential until the mid-19th century, was influenced by Candolle's approach. Darwin's publication of the Origin of Species in 1859 and his concept of common descent required modifications to the Candollean system to reflect evolutionary relationships as distinct from mere morphological similarity.[25]

Botany was greatly stimulated by the appearance of the first "modern" textbook, Matthias Schleiden's Grundzüge der Wissenschaftlichen Botanik, published in English in 1849 as Principles of Scientific Botany.[26] Schleiden was a microscopist and an early plant anatomist who co-founded the cell theory with Theodor Schwann and Rudolf Virchow and was among the first to grasp the significance of the cell nucleus that had been described by Robert Brown in 1831.[27] In 1855, Adolf Fick formulated Fick's laws that enabled the calculation of the rates of molecular diffusion in biological systems.[28]

Echeveria glauca in a Connecticut greenhouse. Botany uses Latin names for identification, here, the specific name glauca means blue.

Late modern botany

Micropropagation of transgenic plants
Micropropagation of transgenic plants

Building upon the gene-chromosome theory of heredity that originated with Gregor Mendel (1822–1884), August Weismann (1834–1914) proved that inheritance only takes place through gametes. No other cells can pass on inherited characters.[29] The work of Katherine Esau (1898–1997) on plant anatomy is still a major foundation of modern botany. Her books Plant Anatomy and Anatomy of Seed Plants have been key plant structural biology texts for more than half a century.[30][31]

The discipline of plant ecology was pioneered in the late 19th century by botanists such as Eugenius Warming, who produced the hypothesis that plants form communities, and his mentor and successor Christen C. Raunkiær whose system for describing plant life forms is still in use today. The concept that the composition of plant communities such as temperate broadleaf forest changes by a process of ecological succession was developed by Henry Chandler Cowles, Arthur Tansley and Frederic Clements. Clements is credited with the idea of climax vegetation as the most complex vegetation that an environment can support and Tansley introduced the concept of ecosystems to biology.[32][33][34] Building on the extensive earlier work of Alphonse de Candolle, Nikolai Vavilov (1887–1943) produced accounts of the biogeography, centres of origin, and evolutionary history of economic plants.[35]

Particularly since the mid-1960s there have been advances in understanding of the physics of plant physiological processes such as transpiration (the transport of water within plant tissues), the temperature dependence of rates of water evaporation from the leaf surface and the molecular diffusion of water vapour and carbon dioxide through stomatal apertures. These developments, coupled with new methods for measuring the size of stomatal apertures, and the rate of photosynthesis have enabled precise description of the rates of gas exchange between plants and the atmosphere.[36][37] Innovations in statistical analysis by Ronald Fisher,[38] Frank Yates and others at Rothamsted Experimental Station facilitated rational experimental design and data analysis in botanical research.[39] The discovery and identification of the auxin plant hormones by Kenneth V. Thimann in 1948 enabled regulation of plant growth by externally applied chemicals. Frederick Campion Steward pioneered techniques of micropropagation and plant tissue culture controlled by plant hormones.[40] The synthetic auxin 2,4-Dichlorophenoxyacetic acid or 2,4-D was one of the first commercial synthetic herbicides.[41]

20th century developments in plant biochemistry have been driven by modern techniques of organic chemical analysis, such as spectroscopy, chromatography and electrophoresis. With the rise of the related molecular-scale biological approaches of molecular biology, genomics, proteomics and metabolomics, the relationship between the plant genome and most aspects of the biochemistry, physiology, morphology and behaviour of plants can be subjected to detailed experimental analysis.[42] The concept originally stated by Gottlieb Haberlandt in 1902[43] that all plant cells are totipotent and can be grown in vitro ultimately enabled the use of genetic engineering experimentally to knock out a gene or genes responsible for a specific trait, or to add genes such as GFP that report when a gene of interest is being expressed. These technologies enable the biotechnological use of whole plants or plant cell cultures grown in bioreactors to synthesise pesticides, antibiotics or other pharmaceuticals, as well as the practical application of genetically modified crops designed for traits such as improved yield.[44]

Modern morphology recognises a continuum between the major morphological categories of root, stem (caulome), leaf (phyllome) and trichome.[45] Furthermore, it emphasises structural dynamics.[46] Modern systematics aims to reflect and discover phylogenetic relationships between plants.[47][48][49][50] Modern Molecular phylogenetics largely ignores morphological characters, relying on DNA sequences as data. Molecular analysis of DNA sequences from most families of flowering plants enabled the Angiosperm Phylogeny Group to publish in 1998 a phylogeny of flowering plants, answering many of the questions about relationships among angiosperm families and species.[51] The theoretical possibility of a practical method for identification of plant species and commercial varieties by DNA barcoding is the subject of active current research.[52][53]

Other Languages
Afrikaans: Plantkunde
Alemannisch: Botanik
አማርኛ: ሥነ ዕጽ
Аҧсшәа: Аботаника
العربية: علم النبات
aragonés: Botanica
arpetan: Botanica
asturianu: Botánica
azərbaycanca: Botanika
Bân-lâm-gú: Si̍t-bu̍t-ha̍k
Basa Banyumasan: Botani
башҡортса: Ботаника
беларуская: Батаніка
беларуская (тарашкевіца)‎: Батаніка
Bislama: Boteni
български: Ботаника
Boarisch: Botanik
bosanski: Botanika
brezhoneg: Louzawouriezh
català: Botànica
Чӑвашла: Ботаника
Cebuano: Botanika
čeština: Botanika
corsu: Botanica
Cymraeg: Botaneg
dansk: Botanik
Deutsch: Botanik
ދިވެހިބަސް: ގަހަވީ އިލްމު
eesti: Botaanika
Ελληνικά: Βοτανική
español: Botánica
Esperanto: Plantoscienco
estremeñu: Botánica
euskara: Botanika
Fiji Hindi: Botany
français: Botanique
Frysk: Botany
furlan: Botaniche
Gàidhlig: Luibh-eòlas
galego: Botánica
한국어: 식물학
hrvatski: Botanika
Ilokano: Botanika
Bahasa Indonesia: Botani
interlingua: Botanica
Interlingue: Botanica
íslenska: Grasafræði
italiano: Botanica
עברית: בוטניקה
Basa Jawa: Botani
Kapampangan: Botany
ქართული: ბოტანიკა
қазақша: Ботаника
Kiswahili: Botania
Kreyòl ayisyen: Etid plant
kurdî: Riweknasî
Кыргызча: Ботаника
кырык мары: Ботаника
Ladino: Botánika
лезги: Ботаника
Latina: Botanice
latviešu: Botānika
Lëtzebuergesch: Botanik
lietuvių: Botanika
Limburgs: Plantkónde
la .lojban.: spaske
lumbaart: Botànica
magyar: Botanika
македонски: Ботаника
მარგალური: ბოტანიკა
Bahasa Melayu: Botani
မြန်မာဘာသာ: ရုက္ခဗေဒ
Nederlands: Plantkunde
नेपाल भाषा: बोतानी
日本語: 植物学
Norfuk / Pitkern: Botenii
norsk: Botanikk
norsk nynorsk: Botanikk
Nouormand: Botannie
Novial: Botanike
occitan: Botanica
олык марий: Ботанике
oʻzbekcha/ўзбекча: Botanika
Pälzisch: Butonik
پنجابی: باٹنی
Patois: Batani
Piemontèis: Botànica
Plattdüütsch: Botanik
polski: Botanika
português: Botânica
română: Botanică
Runa Simi: Butanika
русиньскый: Ботаніка
русский: Ботаника
саха тыла: Ботаника
sardu: Botànica
Scots: Botany
shqip: Botanika
sicilianu: Butànica
Simple English: Botany
slovenčina: Botanika
slovenščina: Botanika
کوردی: ڕوەکناسی
српски / srpski: Ботаника
srpskohrvatski / српскохрватски: Botanika
Basa Sunda: Botani
suomi: Kasvitiede
svenska: Botanik
Tagalog: Botanika
татарча/tatarça: Ботаника
тоҷикӣ: Гиёҳшиносӣ
Türkçe: Botanik
Türkmençe: Botanika
українська: Ботаніка
اردو: نباتیات
vèneto: Botànega
Tiếng Việt: Thực vật học
Volapük: Planav
walon: Botanike
Winaray: Botanika
ייִדיש: באטאניק
粵語: 植物學
Zazaki: Botanik
žemaitėška: Buotanėka
中文: 植物学