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Monday 3 October 2011

Botany

Botany, plant science(s), phytology, or plant biology is a branch of biology that involves the scientific study of plant life. Botany covers a wide range of scientific disciplines concerned with the study of plants, algae and fungi, including structure, growth, reproduction, metabolism, development, diseases, chemical properties, and evolutionary relationships among taxonomic groups. Botany began with early human efforts to identify edible, medicinal and poisonous plants, making it one of the oldest sciences. Today botanists study over 550,000 species of living organisms.

Scope and importance of botany

Hibiscus
As with other life forms in biology, plant life can be studied from different perspectives, from the molecular, genetic and biochemical level through organelles, cells, tissues, organs, individuals, plant populations, and communities of plants. At each of these levels a botanist might be concerned with the classification (taxonomy), structure (anatomy and morphology), or function (physiology) of plant life.
Historically all living things were grouped as animals or plants, and botany covered all organisms not considered animals. Some organisms once included in the field of botany are no longer considered to belong to the plant kingdom – these include fungi (studied in mycology), lichens (lichenology), bacteria (bacteriology), viruses (virology) and single-celled algae, which are now grouped as part of the Protista. However, attention is still given to these groups by botanists, and fungi, lichens, bacteria and photosynthetic protists are usually covered in introductory botany courses.
The study of plants is vital because they are a fundamental part of life on Earth, which generates the oxygen, food, fibres, fuel and medicine that allow humans and other life forms to exist. Through photosynthesis, plants absorb carbon dioxide, a greenhouse gas that in large amounts can affect global climate. Additionally, they prevent soil erosion and are influential in the water cycle. A good understanding of plants is crucial to the future of human societies as it allows us to:

    Produce food to feed an expanding population
    Understand fundamental life processes
    Produce medicine and materials to treat diseases and other ailments
    Understand environmental changes more clearly

Paleobotanists study ancient plants in the fossil record. It is believed that early in the Earth's history, the evolution of photosynthetic plants altered the global atmosphere of the earth, changing the ancient atmosphere by oxidation.

Human nutrition

Nearly all the food we eat comes (directly and indirectly) from 
plants like this American long grain rice
Virtually all foods eaten come from plants, either directly from staple foods and other fruit and vegetables, or indirectly through livestock or other animals, which rely on plants for their nutrition. Plants are the fundamental base of nearly all food chains because they use the energy from the sun and nutrients from the soil and atmosphere, converting them into a form that can be consumed and utilized by animals; this is what ecologists call the first trophic level. Botanists also study how plants produce food we can eat and how to increase yields and therefore their work is important in mankind's ability to feed the world and provide food security for future generations, for example, through plant breeding. Botanists also study weeds, plants which are considered to be a nuisance in a particular location. Weeds are a considerable problem in agriculture, and botany provides some of the basic science used to understand how to minimize 'weed' impact in agriculture and native ecosystems. Ethnobotany is the study of the relationships between plants and people.
Fundamental life processes
Plants are convenient organisms in which fundamental life processes (like cell division and protein synthesis) can be studied, without the ethical dilemmas of studying animals or humans. The genetic laws of inheritanceGregor Mendel, who was studying the way pea shape is inherited. What Mendel learned from studying plants has had far reaching benefits outside of botany. Additionally, Barbara McClintock discovered 'jumping genes' by studying maize. These are a few examples that demonstrate how botanical research has an ongoing relevance to the understanding of fundamental biological processes. were discovered in this way by
Medicine and materials
Many medicinal and recreational drugs, like tetrahydrocannabinol, caffeine, and nicotine come directly from the plant kingdom. Others are simple derivatives of botanical natural products; for example, aspirin is based on the pain killer salicylic acid which originally came from the bark of willow trees. As well, the narcoticanalgesics such as morphine are derived from the opium poppy. There may be many novel cures for diseasesstimulants like coffee, chocolate, tobacco, and tea also come from plants. Most alcoholic beverages come from fermenting plants such as barley (beer), rice (sake) and grapes (wine). provided by plants, waiting to be discovered. Popular
Plants also provide us with many natural materials, such as hemp, cotton, wood, paper, linen, vegetable oils, some types of rope, and rubber. The production of silk would not be possible without the cultivation of the mulberry plant. Sugarcane, rapeseed, soy and other plants with a highly fermentable sugar or oil content have recently been put to use as sources of biofuels, which are important alternatives to fossil fuels (see biodiesel).
Environmental changes
Plants can also help us understand changes in on our environment in many ways.

    Understanding habitat destruction and species extinction is dependent on an accurate and complete catalog of plant systematics and taxonomy.
    Plant responses to ultraviolet radiation can help us monitor problems like ozone depletion.
    Analyzing pollen deposited by plants thousands or millions of years ago can help scientists to reconstruct past climates and predict future ones, an essential part of climate change research.
    Recording and analyzing the timing of plant life cycles are important parts of phenology used in climate-change research.
    Lichens, which are sensitive to atmospheric conditions, have been extensively used as pollution indicators.

In many different ways, plants can act a little like the 'miners' canary', an early warning system alerting us to important changes in our environment. In addition to these practical and scientific reasons, plants are extremely valuable as recreation for millions of people who enjoy gardening, horticultural and culinary uses of plants every day.

Etymology

From Greek βοτάνη = "pasture, grass, fodder", perhaps via the idea of a livestock keeper needing to know which plants are safe for livestock to eat.

History

 
The traditional tools of a botanist
Early botany

Ancient India

Early examples of plant taxonomy occur in the Rigveda, that divides plants into Vṛska (tree), Osadhi (herbs useful to humans) and Virudha (creepers), which are then further subdivided. The Atharvaveda divides plants into eight classes, Visakha (spreading branches), Manjari (leaves with long clusters), Sthambini (bushy plants), Prastanavati (which expands); Ekasṛnga (those with monopodial growth), Pratanavati (creeping plants), Amsumati (with many stalks), and Kandini (plants with knotty joints). The Taittiriya Samhitavṛksa, vana and druma (trees), visakha (shrubs with spreading branches), sasa (herbs), amsumali (a spreading or deliquescent plant), vratati (climber), stambini (bushy plant), pratanavati (creeper), and alasala (those spreading on the ground). classifies the plant kingdom into
Manusmriti – Law book of Hindus – proposed a classification of plants in eight major categories. Charaka Samhitā and Sushruta Samhita and the Vaisesikas also present an elaborate taxonomy.
Parashara, the author of Vṛksayurveda (the science of life of trees), classifies plants into Dvimatrka (Dicotyledons) and Ekamatrka (Monocotyledons). These are further classified into Samiganiya (Fabaceae), Puplikagalniya (Rutaceae), Svastikaganiya (Cruciferae), Tripuspaganiya (Cucurbitaceae), MallikaganiyaApocynaceae), and Kurcapuspaganiya (Asteraceae). (
Important medieval Indian works of plant physiology include the Prthviniraparyam of Udayana, Nyayavindutika of Dharmottara, Saddarsana-samuccaya of Gunaratna, and Upaskara of Sankaramisra.

Ancient Iranic people

The knowledge of medical plants and botany was considered as secret and holy by the ancient Iranic people. There is evidence of such practices in the documents that have survived from the ancient Zoroastrian writings. The practice and use of botany for medical purposes as well as various Iranic cousins and traditions is still common to this day amongst the Iranic people of the Central Asia, Near East and Europe.

Ancient China

In ancient China, the recorded listing of different plants and herb concoctions for pharmaceutical purposes spans back to at least the Warring States (481 BC-221 BC). Many Chinese writers over the centuries contributed to the written knowledge of herbal pharmaceutics. There was the Han Dynasty (202 BC-220 AD) written work of the Huangdi Neijing and the famous pharmacologist Zhang Zhongjing of the 2nd century. There was also the 11th century scientists and statesmen Su Song and Shen Kuo, who compiled treatises on herbal medicine and included the use of mineralogy.

Greco-Roman world

Among the earliest of botanical works in Europe, written around 300 B.C., are two large treatises by Theophrastus: On the History of Plants (Historia Plantarum) and On the Causes of Plants. Together these books constitute the most important contribution to botanical science during antiquity and on into the Middle Ages. Aristotle also wrote about plants. One theory about plants that Greco-Romans came up with about plants was that they ate soil for nutrients.
The Roman medical writer Pedanius Dioscorides (ca.40-90) provides important evidence on Greek and Roman knowledge of medicinal plants. Dioscorides is famous for writing a five volume book in his native Greek Περί ύλης ιατρικής (De Materia Medica - in the Latin translation) that is one of the most influential herbal books in history. In fact, it remained in use until about CE 1600. Approximately 1300-1400 different plant species were known under Roman reign. 

Medieval botany

The earliest known work from the Muslim world dedicated to the study of agriculture was Ibn Wahshiyya's Nabatean Agriculture, which also dealt with the related field of botany and was also an early cookbook.
The Kurdish biologist Abū Ḥanīfa Dīnawarī (828-896) is considered the founder of Arabic botany for his Book of Plants, in which he described at least 637 plants and discussed plant development from germination to death, describing the phases of plant growth and the production of flowers and fruit.
Theophrastus’s Historia Plantarum served as a reference point in botany for many centuries, and was further developed around 1200 A.D. by Giovanni Bodeo da Stapelio, who added a commentarius and drawings: see Historia Plantarum —Selected pages of a 17th century edition of the 1200 A.D. version (in Italian).
Ibn Bassal is known for his famous work named The Classification of Soils. Al-Asma'i was the earliest known Arab biologist, botanist and zoologist. al-Masihi was the first to recognize the science of Botany.[citation needed]
In the early 13th century, the Andalusian-Arabian biologist Abu al-Abbas al-Nabati developed an early scientific method for botany, introducing empirical and experimental techniques in the testing, description and identification of numerous materia medica, and separating unverified reports from those supported by actual tests and observations.His student Ibn al-Baitar (d. 1248) wrote a pharmaceutical encyclopedia describing 1,400 plants, foods, and drugs, 300 of which were his own original discoveries. A Latin translation of his work was useful to European biologists and pharmacists in the 18th and 19th centuries.

Early modern botany

Crantz's Classis cruciformium..., 1769
German physician Leonhart Fuchs (1501–1566) was one of the three founding fathers of botany, along with Otto Brunfels (1489- 1534) and Hieronymus Bock (1498–1554) (also called Hieronymus Tragus)
Valerius Cordus (1515–1554) authored one of the greatest pharmacopoeias and one of the most celebrated herbals in history, Dispensatorium (1546). As early as the 16th century, the Italian Ulisse Aldrovandi was scientifically researching plants. In 1665, using an early microscope, Robert Hooke discovered cells in cork, and a short time later in living plant tissue. The Germans Jacob Theodor Klein and Leonhart Fuchs, the Swiss Conrad von Gesner, and the British author Nicholas Culpeper published herbals that gave information on the medicinal uses of plants.
During the 18th century systems of classification became deliberately artificial and served only for the purpose of identification. These classifications are comparable to diagnostic keys, where taxa are artificially grouped in pairs by few, easily recognisable characters. The sequence of the taxa in keys is often totally unrelated to their natural or phyletic groupings. In the 18th century an increasing number of new plants had arrived in Europe, from newly discovered countries and the European colonies worldwide, and a larger amount of plants became available for study.
In 1754 Carl von Linné (Carl Linnaeus) divided the plant Kingdom into 25 classes. One, the Cryptogamia, included all the plants with concealed reproductive parts (algae, fungi, mosses and liverworts and ferns).more natural affinities between plants, than the sexual system of Linnaeus indicated. Adanson (1763), de JussieuCandolle (1819) all proposed various alternative natural systems that were widely followed. The ideas of natural selection as a mechanism for evolution required adaptations to the Candollean system, which started the studies on evolutionary relationships and phylogenetic classifications of plants. (1789),

Modern botany

A considerable amount of new knowledge today is being generated from studying model plants like Arabidopsis thaliana. This weedy species in the mustard family was one of the first plants to have its genomerice (Oryza sativa) genome, its relatively small genome, and a large international research community have made rice an important cereal/grass/monocot model.[13] Another grass species, Brachypodium distachyon is also emerging as an experimental model for understanding the genetic, cellular and molecular biology of temperate grasses. Other commercially important staple foods like wheat, maize, barley, rye, pearl millet and soybean are also having their genomes sequenced. Some of these are challenging to sequence because they have more than two haploid (n) sets of chromosomes, a condition known as polyploidy, common in the plant kingdom. Chlamydomonas reinhardtii (a single-celled, green alga) is another plant model organism that has been extensively studied and provided important insights into cell biology. sequenced. The sequencing of the
In 1998 the Angiosperm Phylogeny Group published a phylogeny of flowering plants based on an analysis of DNA sequences from most families of flowering plants. As a result of this work, major questions such as which families represent the earliest branches in the genealogy of angiosperms are now understood. Investigating how plant species are related to each other allows botanists to better understand the process of evolution in plants.

Subdisciplines of botany


    Agronomy — Application of plant science to crop production
    Bryology — Mosses, liverworts, and hornworts
    Economic botany — Study of plants of economic use or value
    Ethnobotany — Relationship between humans and plants
    Forestry — Forest management and related studies
    Horticulture — Cultivated plants
    Lichenology — The study of lichens
    Paleobotany — Fossil plants
    Palynology — Pollen and spores

   

    Phycology — Algae
    Phytochemistry — Plant secondary chemistry and chemical processes
    Phytopathology — Plant diseases
    Plant anatomy — Cell and tissue structure
    Plant ecology — Role of plants in the environment
    Plant genetics — Genetic inheritance in plants
    Plant morphology — Structure and life cycles
    Plant physiology — Life functions of plants
    Plant systematics — Classification and naming of plants

Notable botanists

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