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110-482: Based on the similarities in their flora, botanist Ronald D'Oyley Good identified a separate Antarctic Floristic Kingdom that included southern South America, New Zealand, and some southern island groups. In addition, Australia was determined to be its own floristic kingdom because of the influx of tropical Eurasian flora that had mostly supplanted the Antarctic flora and included New Guinea and New Caledonia in

220-490: A botanically and pharmacologically important herbal Historia Plantarum in 1544 and a pharmacopoeia of lasting importance, the Dispensatorium in 1546. Naturalist Conrad von Gesner (1516–1565) and herbalist John Gerard (1545– c.  1611 ) published herbals covering the supposed medicinal uses of plants. Naturalist Ulisse Aldrovandi (1522–1605) was considered the father of natural history , which included

330-414: A considerable problem in agriculture, and the biology and control of plant pathogens in agriculture and natural ecosystems . Ethnobotany is the study of the relationships between plants and people. When applied to the investigation of historical plant–people relationships ethnobotany may be referred to as archaeobotany or palaeoethnobotany . Some of the earliest plant-people relationships arose between

440-452: A continuum between the major morphological categories of root, stem (caulome), leaf (phyllome) and trichome . Furthermore, it emphasises structural dynamics. Modern systematics aims to reflect and discover phylogenetic relationships between plants. 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

550-400: 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. For the purposes of identification, Linnaeus's Systema Sexuale classified plants into 24 groups according to

660-570: A legacy of the ancient supercontinent of Gondwana , a landmass formerly composed of South America, Africa, India, Antarctica and Australia. The high degree of endemic species and monospecific genera is thought to be linked to the geographic isolation came into being as result of the uplift of the Andes . There are a few " boreal " components in the Valdivian temperate rain forest which arrived by long-distance transport. Yet another component are

770-404: A plant sucks water through them under water stress. Lignin is also used in other cell types like sclerenchyma fibres that provide structural support for a plant and is a major constituent of wood. Sporopollenin is a chemically resistant polymer found in the outer cell walls of spores and pollen of land plants responsible for the survival of early land plant spores and the pollen of seed plants in

880-552: A polymer of fructose is used for the same purpose in the sunflower family Asteraceae . Some of the glucose is converted to sucrose (common table sugar) for export to the rest of the plant. Unlike in animals (which lack chloroplasts), plants and their eukaryote relatives have delegated many biochemical roles to their chloroplasts , including synthesising all their fatty acids , and most amino acids . The fatty acids that chloroplasts make are used for many things, such as providing material to build cell membranes out of and making

990-464: A process that generates molecular oxygen (O 2 ) as a by-product. The light energy captured by chlorophyll a is initially in the form of electrons (and later a proton gradient ) that's used to make molecules of ATP and NADPH which temporarily store and transport energy. Their energy is used in the light-independent reactions of the Calvin cycle by the enzyme rubisco to produce molecules of

1100-505: A pure form of carbon made by pyrolysis of wood, has a long history as a metal- smelting fuel, as a filter material and adsorbent and as an artist's material and is one of the three ingredients of gunpowder . Cellulose , the world's most abundant organic polymer, can be converted into energy, fuels, materials and chemical feedstock. Products made from cellulose include rayon and cellophane , wallpaper paste , biobutanol and gun cotton . Sugarcane , rapeseed and soy are some of

1210-543: A relatively narrow Chilean coastal strip, between the Pacific Ocean to the west and the southern Andes Mountains to the east, from roughly 37° to 48° south latitude. North of 42°, the Chilean Coast Range stretches on, with just the north–south running Chilean Central Valley between it and the Andes. South of 42°, the coast range continues as a chain of offshore islands (including Chiloé Island and

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1320-536: 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". 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. Another work from Ancient Greece that made an early impact on botany

1430-460: A useful proxy for temperature in historical climatology , and the biological impact of climate change and global warming . Palynology , the analysis of fossil pollen deposits in sediments from thousands or millions of years ago allows the reconstruction of past climates. Estimates of atmospheric CO 2 concentrations since the Palaeozoic have been obtained from stomatal densities and

1540-1010: A variety of spatial scales in groups, populations and communities that collectively constitute vegetation. Regions with characteristic vegetation types and dominant plants as well as similar abiotic and biotic factors, climate , and geography make up biomes like tundra or tropical rainforest . Herbivores eat plants, but plants can defend themselves and some species are parasitic or even carnivorous . Other organisms form mutually beneficial relationships with plants. For example, mycorrhizal fungi and rhizobia provide plants with nutrients in exchange for food, ants are recruited by ant plants to provide protection, honey bees , bats and other animals pollinate flowers and humans and other animals act as dispersal vectors to spread spores and seeds . Plant responses to climate and other environmental changes can inform our understanding of how these changes affect ecosystem function and productivity. For example, plant phenology can be

1650-464: A variety of broadleaf evergreen trees, including Laureliopsis philippiana , Aextoxicon punctatum , Eucryphia cordifolia , Caldcluvia paniculata , and Weinmannia trichosperma , with an understory of Myrceugenia planipes , the arrayán ( Luma apiculata ) and other plants. Old-growth Valdivian evergreen forest (siempreverde) tend to form stratified canopy made up of two or three layers. Patagonian Andean forests . The third forest type

1760-628: A way of drug discovery . Plants can synthesise coloured dyes and pigments such as the anthocyanins responsible for the red colour of red wine , yellow weld and blue woad used together to produce Lincoln green , indoxyl , source of the blue dye indigo traditionally used to dye denim and the artist's pigments gamboge and rose madder . Sugar, starch , cotton, linen , hemp , some types of rope , wood and particle boards , papyrus and paper, vegetable oils , wax , and natural rubber are examples of commercially important materials made from plant tissues or their secondary products. Charcoal ,

1870-456: 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 Bentham & Hooker system , 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

1980-406: Is De materia medica , a five-volume encyclopedia about preliminary 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. Important contributions from the medieval Muslim world include Ibn Wahshiyya 's Nabatean Agriculture , Abū Ḥanīfa Dīnawarī 's (828–896)

2090-405: Is peppermint , Mentha × piperita , a sterile hybrid between Mentha aquatica and spearmint, Mentha spicata . The many cultivated varieties of wheat are the result of multiple inter- and intra- specific crosses between wild species and their hybrids. Angiosperms with monoecious flowers often have self-incompatibility mechanisms that operate between the pollen and stigma so that

2200-428: Is a bamboo that grows in humid areas below 500 m, where Chusquea culeou becomes more dominant above. Chusquea quila can form pure stands called quilantales . Very few plants can grow under this species. Other notable species are the nalca or Chilean rhubarb ( Gunnera tinctoria ) and the ferns Lophosoria quadripinnata and Parablechnum cordatum . Chile's national flower, the copihue ( Lapageria rosea )

2310-445: Is a pioneer species that grows in disturbed areas of the Valdivian rain forest. The maximum plant species richness is found at latitudes 40 to 43° S. There are four main types of forest ecosystems in the Valdivian ecoregion. Deciduous forests . At the northern end of the ecoregion are deciduous forests, dominated by deciduous species of southern beech , including rauli ( Nothofagus alpina ) and roble ( N. obliqua ). This

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2420-476: Is a broad, multidisciplinary subject with contributions and insights 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 study

2530-514: Is a low diversity of mammals in Chilean temperate forests. The slender-billed parakeet ( Enicognathus leptorhynchus ) is endemic. Near-endemic and limited-range birds include the Chilean pigeon ( Patagioenas araucana ), Black-throated huet-huet ( Pteroptochos tarnii ), Chucao tapaculo ( Scelorchilus rubecula ), and Ochre-flanked tapaculo ( Eugralla paradoxa ). Hummingbirds are common in

2640-597: Is a transitional zone to the Mediterranean-climate region to the north. It grows from 35 to 36º S latitude along Chilean Coast Range , where it is known as Maulino forest . Nothofagus glauca and N. Alessandrii are predominant trees in Maulino forest. Deciduous Nothofagus forests also grow along the Andes of central Chile as far north as 33º S latitude, from approximately 1,200 meters elevation up to

2750-467: Is at about 2,400 m in the northern part of the ecoregion (35° S), and descends to 1,000 m in the south of the Valdivian region. The Valdivian temperate rain forests are temperate broadleaf and mixed forests . The Valdivian and Magellanic temperate rainforests are the only temperate rain forests in South America and one of a small number of temperate rain forests in the world. Together they are

2860-762: Is gathered by ethnobotanists. This information can relay a great deal of information on how the land once was thousands of years ago and how it has changed over that time. The goals of plant ecology are to understand the causes of their distribution patterns, productivity, environmental impact, evolution, and responses to environmental change. Plants depend on certain edaphic (soil) and climatic factors in their environment but can modify these factors too. For example, they can change their environment's albedo , increase runoff interception, stabilise mineral soils and develop their organic content, and affect local temperature. Plants compete with other organisms in their ecosystem for resources. They interact with their neighbours at

2970-451: 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. 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

3080-400: Is still given to these groups by botanists, and fungi (including lichens) and photosynthetic protists are usually covered in introductory botany courses. Palaeobotanists study ancient plants in the fossil record to provide information about the evolutionary history of plants . Cyanobacteria , the first oxygen-releasing photosynthetic organisms on Earth, are thought to have given rise to

3190-444: 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. Building on

3300-616: Is suggested a paleobotanical habitat similar to the extant cool temperate Valdivian rainforests . During the colder Neogene (17–2.5 Ma), a low diversity tundra ecosystem dominated by angiosperms replaced the rainforests. There are two conifer and at least seven angiosperm morphotypes recorded in the Antarctica palaeoflora. Conifers include Cupressinoxylon , which is the more common, and Podocarpoxylon . The angiosperm component includes two species of Nothofagoxylon , one species of Myrceugenelloxylon (similar to Luma , in

3410-482: Is the Patagonian Andean forests , which are distributed at higher elevations along the Andes mountain front, and are dominated by evergreen conifers , including pehuén ( Araucaria araucana ) and alerce ( Fitzroya cupressoides ). The alerce looks like a giant sequoia , and is a rival in longevity to the bristlecone pine , some with growth rings recording 3,625 years of local weather cycles. Closer to

Antarctic flora - Misplaced Pages Continue

3520-502: 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 botanē ( βοτάνη ) meaning " pasture ", " herbs " " grass ", or " fodder "; Botanē is in turn derived from boskein ( Greek : βόσκειν ), "to feed" or "to graze ". Traditionally, botany has also included

3630-498: Is the study of ferns and allied plants. A number of other taxa of ranks varying from family to subgenus have terms for their study, including agrostology (or graminology) for the study of grasses, synantherology for the study of composites, and batology for the study of brambles. Study can also be divided by guild rather than clade or grade . Dendrology is the study of woody plants. Many divisions of biology have botanical subfields. These are commonly denoted by prefixing

3740-564: 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. 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. Botany is divided along several axes. Some subfields of botany relate to particular groups of organisms. Divisions related to

3850-577: The Antarctic Circumpolar Current to form, which isolated Antarctica climatically and caused it to become much colder. The Antarctic flora subsequently died out in Antarctica, but is still an important component of the flora of southern Neotropic (South America) and Australasian realms , which were also former parts of Gondwana. Some genera which originated in Antarctic Flora are still recognized as major components of

3960-499: 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. 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

4070-417: The C 4 carbon fixation pathway for photosynthesis which avoid the losses resulting from photorespiration in the more common C 3 carbon fixation pathway. These biochemical strategies are unique to land plants. Phytochemistry is a branch of plant biochemistry primarily concerned with the chemical substances produced by plants during secondary metabolism . Some of these compounds are toxins such as

4180-709: The Chonos Archipelago ), while the "Central Valley" is submerged and continues as the Gulf of Corcovado . Much of the ecoregion was once covered by the Patagonian Ice Sheet and other glaciers during the peak of the last ice age , with ice descending from the Andes mountains; numerous bodies of water within the Chilean Lake District (in the central part of the ecoregion) are the remnants of ancient glacial valleys. The southern part of

4290-868: The Pacific Plate ), the coast-hugging temperate rainforests of the Pacific Northwest (from Northern California to Southern Alaska , roughly 40°-60° north latitude) exist in similar settings, with the Rocky Mountains to the east and the Pacific Ocean to the west. East of the Rocky Mountains, the North American prairie grassland stretches from south-central Canada to Texas , not unlike the Argentine grasslands to

4400-556: The Paleotropical floristic kingdom. Millions of years ago the climate in Antarctica was warmer, and was able to support flora well into the Neogene . This included forests of podocarps and southern beech . Antarctica was also part of the ancient supercontinent of Gondwana, which gradually broke up by plate tectonics starting 110 million years ago. The separation of South America from Antarctica 30–35 million years ago allowed

4510-504: The alkaloid coniine from hemlock . Others, such as the essential oils peppermint oil and lemon oil are useful for their aroma, as flavourings and spices (e.g., capsaicin ), and in medicine as pharmaceuticals as in opium from opium poppies . Many medicinal and recreational drugs , such as tetrahydrocannabinol (active ingredient in cannabis ), caffeine , morphine and nicotine come directly from plants. Others are simple derivatives of botanical natural products. For example,

Antarctic flora - Misplaced Pages Continue

4620-565: 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 . The synthetic auxin 2,4-dichlorophenoxyacetic acid or 2,4-D was one of the first commercial synthetic herbicides . 20th century developments in plant biochemistry have been driven by modern techniques of organic chemical analysis , such as spectroscopy , chromatography and electrophoresis . With

4730-626: 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. In 1855, Adolf Fick formulated Fick's laws that enabled the calculation of the rates of molecular diffusion in biological systems. 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. The work of Katherine Esau (1898–1997) on plant anatomy

4840-444: The cellulose and lignin used to build their bodies, and secondary products like resins and aroma compounds . Plants and various other groups of photosynthetic eukaryotes collectively known as " algae " have unique organelles known as chloroplasts . Chloroplasts are thought to be descended from cyanobacteria that formed endosymbiotic relationships with ancient plant and algal ancestors. Chloroplasts and cyanobacteria contain

4950-427: The indigenous people of Canada in identifying edible plants from inedible plants. This relationship the indigenous people had with plants was recorded by ethnobotanists. Plant biochemistry is the study of the chemical processes used by plants. Some of these processes are used in their primary metabolism like the photosynthetic Calvin cycle and crassulacean acid metabolism . Others make specialised materials like

5060-426: The pines , and flowering plants ) and the free-sporing cryptogams including ferns , clubmosses , liverworts , hornworts and mosses . Embryophytes are multicellular eukaryotes descended from an ancestor that obtained its energy from sunlight by photosynthesis . They have life cycles with alternating haploid and diploid phases. The sexual haploid phase of embryophytes, known as the gametophyte , nurtures

5170-540: The refugia of the Valdivian temperate rain forest between latitudes 41 and 37° S were; the coastal region, the lower slopes of the Chilean Coast Range and the westernmost Chilean Central Valley all of which remained free of disturbance by the glacial, glacifluvial and periglacial disturbance through the glaciation. Some of the threatened mammals of the Valdivian forests include the monito del monte (Dromiciops gliroides) , an arboreal marsupial ,

5280-600: The southern pudú (Pudu puda) the world's smallest deer , and the kodkod (Leopardus guigna) , South America's smallest cat . Since the beginning of the 20th century, there have also been nonnative wild boars living in the Valdivian forests. The Chilean climbing mouse ( Irenomys tarsalis ) and Chilean shrew opossum ( Rhyncholestes raphanurus ) are endemic to the ecoregion. Most mammal genera in Valdivian forests are also found in semi-arid parts of Patagonia . Relative to similar forest in North America there

5390-455: The tree line at 2,400 meters elevation. A krummholz of Nothofagus antarctica and N. pumilio grows near the tree line. The southern limit of these forests is 38º S latitude. Tall coniferous pehuén monkey-puzzle trees ( Araucaria araucana ) grow at the southern edge of the deciduous forests, from the coast at Nahuelbuta National Park to the Andes. Valdivian laurel-leaved forests . Valdivian laurel-leaved forests , characterized by

5500-456: The windward slope of the Chilean Coast Range and the Andes , creating orographic rainfall . Average annual precipitation varies from 1,000 mm at the northern edge of the ecoregion to more than 6,000 mm per year in the south. The northern portion of the ecoregion has a Submediterranean climate , with rainfall concentrated in the winter months. This seasonality decreases towards the south. Average annual temperatures are fairly uniform within

5610-408: The 3-carbon sugar glyceraldehyde 3-phosphate (G3P). Glyceraldehyde 3-phosphate is the first product of photosynthesis and the raw material from which glucose and almost all other organic molecules of biological origin are synthesised. Some of the glucose is converted to starch which is stored in the chloroplast. Starch is the characteristic energy store of most land plants and algae, while inulin ,

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5720-517: The Candollean system to reflect evolutionary relationships as distinct from mere morphological similarity. 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 . Schleiden was a microscopist and an early plant anatomist who co-founded

5830-411: The Valdivian forests because of the presence of plants like the maqui ( Aristotelia chilensis ) and the copihue . The Valdivian forests include stands of huge trees, especially Nothofagus and Fitzroya , which can live to a great age. These magnificent rainforests are endangered by extensive logging and their replacement by fast-growing pines and eucalyptus , which are more sought-after by

5940-482: The Vegetable Kingdom at the start of chapter XII noted "The first and most important of the conclusions which may be drawn from the observations given in this volume, is that generally cross-fertilisation is beneficial and self-fertilisation often injurious, at least with the plants on which I experimented." An important adaptive benefit of outcrossing is that it allows the masking of deleterious mutations in

6050-412: The above pair of categories gives rise to fields such as bryogeography (the study of the distribution of mosses). Different parts of plants also give rise to their own subfields, including xylology , carpology (or fructology) and palynology , these been the study of wood, fruit and pollen/spores respectively. Botany also overlaps on the one hand with agriculture, horticulture and silviculture, and on

6160-439: The ancestor of plants by entering into an endosymbiotic relationship with an early eukaryote, ultimately becoming the chloroplasts in plant cells. The new photosynthetic plants (along with their algal relatives) accelerated the rise in atmospheric oxygen started by the cyanobacteria , changing the ancient oxygen-free, reducing , atmosphere to one in which free oxygen has been abundant for more than 2 billion years. Among

6270-407: The area, especially at coastal locations where annual temperature differences between localities never exceed 7 °C. The northward-flowing oceanic Humboldt Current creates humid and foggy conditions near the coast. In the summer the temperature can climb to 16.5 °C (62 °F), while during winter the temperature can drop below 7 °C (45 °F). Winter temperatures are lower at higher elevations. The tree line

6380-447: The base of most 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 used by animals. This is what ecologists call the first trophic level . The modern forms of the major staple foods , such as hemp , teff , maize, rice, wheat and other cereal grasses, pulses , bananas and plantains, as well as hemp , flax and cotton grown for their fibres, are

6490-500: The blue-green pigment chlorophyll a . Chlorophyll a (as well as its plant and green algal-specific cousin chlorophyll b ) absorbs light in the blue-violet and orange/red parts of the spectrum while reflecting and transmitting the green light that we see as the characteristic colour of these organisms. The energy in the red and blue light that these pigments absorb is used by chloroplasts to make energy-rich carbon compounds from carbon dioxide and water by oxygenic photosynthesis ,

6600-446: The broader historical sense of botany include bacteriology , mycology (or fungology) and phycology - the study of bacteria, fungi and algae respectively - with lichenology as a subfield of mycology. The narrower sense of botany in the sense of the study of embryophytes (land plants) is disambiguated as phytology. Bryology is the study of mosses (and in the broader sense also liverworts and hornworts). Pteridology (or filicology)

6710-513: 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. 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 Linnaeus published his Species Plantarum ,

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6820-461: The developing diploid embryo sporophyte within its tissues for at least part of its life, even in the seed plants, where the gametophyte itself is nurtured by its parent sporophyte. Other groups of organisms that were previously studied by botanists include bacteria (now studied in bacteriology ), fungi ( mycology ) – including lichen -forming fungi ( lichenology ), non- chlorophyte algae ( phycology ), and viruses ( virology ). However, attention

6930-463: 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 nomenclature of Carl Linnaeus that remains in use to this day for the naming of all biological species. In the 19th and 20th centuries, new techniques were developed for

7040-577: The east of the Andes. Similar to the Atacama region of Chile, the Baja California and Sonoran deserts in the US/Mexican states of California and Baja California act as climatic borders for the northwest’s rainforests. Since the forest is located at around 40 degrees south, it is strongly influenced by the westerlies . The water vapour held by the westerlies condenses as they encounter

7150-419: The efforts of early humans to identify – and later cultivate – plants that were edible, poisonous, and possibly medicinal, making it one of the first endeavours of human investigation. Medieval physic gardens , often attached to monasteries , contained plants possibly having medicinal benefit. They were forerunners of the first botanical gardens attached to universities , founded from the 1540s onwards. One of

7260-603: The end of the Cretaceous, South America and Australia were still joined to Antarctica. Paleontologist Gilbert Brenner identified the emergence of a distinct southern Gondwanan flora by the late Cretaceous period in the cooler and humid southern hemisphere regions of Australia, southern South America, southern Africa, Antarctica, and New Zealand; it most resembled the flora of modern-day southern New Zealand. A drier northern Gondwanan flora had developed in northern South America and northern Africa. Africa and India drifted north into

7370-408: The equator, incidents of endemism becoming more frequent as one moves equatorward. Lowland soils near the coast contain more available nutrients than more inland soils. The flora of the forests has inherited and developed its characteristics due to a variety of causes. Its Neotropical affinities reflect its current geographic connection to the remaining South America. Its "Gondwanan" species are

7480-899: The extant family Myrtaceae ), and one species of Weinmannioxylon (similar to Eucryphia in the extant family Cunoniaceae). Two other species are assigned to genera Hedycaryoxylon ( Monimiaceae ) and Atherospermoxylon ( Atherospermataceae ). A fossil water lily , Notonuphar (similar to Nuphar in the extant family Nympheaceae ), was described from Eocene -aged sediments on Seymour Island in 2017. Antarctica's extant flora presently consists of around 100 mosses , 25-30 liverworts , and around 700 terrestrial and aquatic algal species. In addition, there are around 250 lichens . Species of moss endemic to Antarctica include Grimmia antarctici , Schistidium antarctici , and Sarconeurum glaciale . Just two native flowering plants, Deschampsia antarctica (Antarctic hair grass) and Colobanthus quitensis (Antarctic pearlwort), are found on

7590-453: 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. 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

7700-429: The flora of New Caledonia, Tasmania , Madagascar , India , New Zealand, and southern South America. South America, Madagascar, Africa, India, Australia, New Zealand, and Antarctica were all part of the supercontinent Gondwana, which started to break up in the early Cretaceous period (145–66 million years ago). India was the first to break away, followed by Africa, and then New Zealand, which started to drift north. By

7810-430: The form of ice. However, with the onset of anthropogenic warming , this "vegetation cover increased from 0.863 kilometers in 1986 to 11.947 kilometers in 2021, with an accelerated rate of change in recent years (2016–2021: 0.424 kilometers per year) relative to the study period (1986–2021: 0.317 km per year)." Botanist Botany , also called plant science (or plant sciences ), plant biology or phytology ,

7920-575: The fossil record. It is widely regarded as a marker for the start of land plant evolution during the Ordovician period. The concentration of carbon dioxide in the atmosphere today is much lower than it was when plants emerged onto land during the Ordovician and Silurian periods. Many monocots like maize and the pineapple and some dicots like the Asteraceae have since independently evolved pathways like Crassulacean acid metabolism and

8030-451: The functional relationships between plants and their habitats  – the environments where they complete their life cycles . Plant ecologists study the composition of local and regional floras , their biodiversity , genetic diversity and fitness , the adaptation of plants to their environment, and their competitive or mutualistic interactions with other species. Some ecologists even rely on empirical data from indigenous people that

8140-416: The genome of progeny. This beneficial effect is also known as hybrid vigor or heterosis. Once outcrossing is established, subsequent switching to inbreeding becomes disadvantageous since it allows expression of the previously masked deleterious recessive mutations, commonly referred to as inbreeding depression. Valdivian temperate forests The Valdivian temperate forests (NT0404) is an ecoregion on

8250-444: The global carbon and water cycles and plant roots bind and stabilise soils, preventing soil erosion . Plants are crucial to the future of human society as they provide food, oxygen, biochemicals , and products for people, as well as creating and preserving soil. Historically, all living things were classified as either animals or plants and botany covered the study of all organisms not considered animals. Botanists examine both

8360-621: The important botanical questions of the 21st century are the role of plants as primary producers in the global cycling of life's basic ingredients: energy, carbon, oxygen, nitrogen and water, and ways that our plant stewardship can help address the global environmental issues of resource management , conservation , human food security , biologically invasive organisms , carbon sequestration , climate change , and sustainability . Virtually all staple foods come either directly from primary production by plants, or indirectly from animals that eat them. Plants and other photosynthetic organisms are at

8470-478: The internal functions and processes within plant organelles , cells, tissues, whole plants, plant populations and plant communities. At each of these levels, a botanist may be concerned with the classification ( taxonomy ), phylogeny and evolution , structure ( anatomy and morphology ), or function ( physiology ) of plant life. The strictest definition of "plant" includes only the "land plants" or embryophytes , which include seed plants (gymnosperms, including

8580-403: The leaf shapes and sizes of ancient land plants . Ozone depletion can expose plants to higher levels of ultraviolet radiation-B (UV-B), resulting in lower growth rates. Moreover, information from studies of community ecology , plant systematics , and taxonomy is essential to understanding vegetation change , habitat destruction and species extinction . Inheritance in plants follows

8690-576: 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. Innovations in statistical analysis by Ronald Fisher , Frank Yates and others at Rothamsted Experimental Station facilitated rational experimental design and data analysis in botanical research. The discovery and identification of

8800-576: The maintenance of biodiversity . Botany originated as herbalism , the study and use of plants for their possible medicinal properties . 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 BCE, Ancient Egypt , in archaic Avestan writings, and in works from China purportedly from before 221 BCE. Modern botany traces its roots back to Ancient Greece specifically to Theophrastus ( c.  371 –287 BCE),

8910-493: The major groups of organisms that carry out photosynthesis , a process that uses the energy of sunlight to convert water and carbon dioxide into sugars that can be used both as a source of chemical energy and of organic molecules that are used in the structural components of cells. As a by-product of photosynthesis, plants release oxygen into the atmosphere, a gas that is required by nearly all living things to carry out cellular respiration. In addition, they are influential in

9020-474: 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

9130-472: The northern and western parts of the Antarctic Peninsula . The continent of Antarctica itself has been too cold and dry to support any other vascular plants for millions of years. The scanty vegetation of Antarctica is a result of the chilling temperature, lack of sunlight, little rainfall, relatively poor soil quality , and a lack of moisture due to the inability of the plants to absorb water in

9240-596: The number of their male sexual organs. The 24th group, Cryptogamia , included all plants with concealed reproductive parts, mosses , liverworts , ferns , algae and fungi . Botany was originally a hobby for upper-class women. These women would collect and paint flowers and plants from around the world with scientific accuracy. The paintings were used to record many species that could not be transported or maintained in other environments. Marianne North illustrated over 900 species in extreme detail with watercolor and oil paintings. Her work and many other women's botany work

9350-447: The other hand with medicine and pharmacology, giving rise to fields such as agronomy , horticultural botany, phytopathology and phytopharmacology . The study of plants is vital because they underpin almost all animal life on Earth by generating a large proportion of the oxygen and food that provide humans and other organisms with aerobic respiration with the chemical energy they need to exist. Plants, algae and cyanobacteria are

9460-404: The outcome of prehistoric selection over thousands of years from among wild ancestral plants with the most desirable characteristics. Botanists study how plants produce food and how to increase yields, for example through plant breeding , making their work important to humanity's ability to feed the world and provide food security for future generations. Botanists also study weeds, which are

9570-791: The pain killer aspirin is the acetyl ester of salicylic acid , originally isolated from the bark of willow trees, and a wide range of opiate painkillers like heroin are obtained by chemical modification of morphine obtained from the opium poppy . Popular stimulants come from plants, such as caffeine from coffee, tea and chocolate, and nicotine from tobacco. Most alcoholic beverages come from fermentation of carbohydrate -rich plant products such as barley (beer), rice ( sake ) and grapes (wine). Native Americans have used various plants as ways of treating illness or disease for thousands of years. This knowledge Native Americans have on plants has been recorded by enthnobotanists and then in turn has been used by pharmaceutical companies as

9680-490: The plants with a highly fermentable sugar or oil content that are used as sources of biofuels , important alternatives to fossil fuels , such as biodiesel . Sweetgrass was used by Native Americans to ward off bugs like mosquitoes . These bug repelling properties of sweetgrass were later found by the American Chemical Society in the molecules phytol and coumarin . Plant ecology is the science of

9790-486: The pollen either fails to reach the stigma or fails to germinate and produce male gametes . This is one of several methods used by plants to promote outcrossing . In many land plants the male and female gametes are produced by separate individuals. These species are said to be dioecious when referring to vascular plant sporophytes and dioicous when referring to bryophyte gametophytes . Charles Darwin in his 1878 book The Effects of Cross and Self-Fertilization in

9900-442: The polymer cutin which is found in the plant cuticle that protects land plants from drying out. Plants synthesise a number of unique polymers like the polysaccharide molecules cellulose , pectin and xyloglucan from which the land plant cell wall is constructed. Vascular land plants make lignin , a polymer used to strengthen the secondary cell walls of xylem tracheids and vessels to keep them from collapsing when

10010-556: The practical value of earlier "physic gardens", often associated with monasteries, in which plants were cultivated for suspected medicinal uses. They supported the growth of botany as an academic subject. Lectures were given about the plants grown in the gardens. Botanical gardens came much later to northern Europe; the first in England was the University of Oxford Botanic Garden in 1621. German physician Leonhart Fuchs (1501–1566)

10120-643: The pulp and paper industry. The native trees that are cleared to make way for these monocultures are often exported as woodchips to Japan. A start at conservation was made in November 2003 when a consortium of conservation groups, both local and international, bought at auction of a bankrupt logging firm 147,500 acres (600 km ) of biologically rich rainforest in the Valdivian Coastal Range. Gianni Lopez, Executive Director of CONAMA , Chile's national environmental agency remarked, "Ten years ago

10230-674: The region features many glacier-carved fjords . To the north, the Valdivian forests give way to the Mediterranean forests, woodlands, and scrub of the Chilean Matorral ecoregion. A few coastal enclaves of Valdivian forest grow in north-central Chile (such as Bosque de Fray Jorge National Park ) as remains of the last glacial maximum . To the south lies the Magellanic subpolar forests ecoregion. The temperate Valdivian, matorral, and Magellanic ecoregions are isolated from

10340-461: 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. The concept originally stated by Gottlieb Haberlandt in 1902 that all plant cells are totipotent and can be grown in vitro ultimately enabled

10450-680: The same fundamental principles of genetics as in other multicellular organisms. Gregor Mendel discovered the genetic laws of inheritance by studying inherited traits such as shape in Pisum sativum ( peas ). What Mendel learned from studying plants has had far-reaching benefits outside of botany. Similarly, " jumping genes " were discovered by Barbara McClintock while she was studying maize. Nevertheless, there are some distinctive genetic differences between plants and other organisms. Species boundaries in plants may be weaker than in animals, and cross species hybrids are often possible. A familiar example

10560-519: The second largest in the world, after the Pacific temperate rain forests of North America (which stretches from Alaska to northern California). The Valdivian forests are a refuge for the Antarctic flora , and share many plant families with the temperate rainforests of New Zealand , Tasmania , and Australia . Fully half the species of woody plants are endemic to this ecoregion. Chusquea quila

10670-552: The species from nearby South American ecosystems that adapted to the temperate rainforest. During the Llanquihue glaciation much of the area west of Llanquihue Lake remained ice-free during the Last Glacial Maximum and had sparsely distributed vegetation dominated by Nothofagus species. Valdivian temperate rain forest proper was reduced to scattered remnants in to the west of the Andes. More specifically

10780-603: 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 , including some 391,000 species of vascular plants (of which approximately 369,000 are flowering plants ) and approximately 20,000 bryophytes . Botany originated in prehistory as herbalism with

10890-450: 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

11000-471: 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. 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

11110-527: The subtropical/tropical forests that dominate northern South America by such landscapes as the Atacama desert (north of the matorral), the Andes Mountains, and the dry, rain-shadow Patagonian steppe east of the Andes. As a result, the temperate forest regions have evolved in relative isolation, with a high degree of endemic species. Due to a similar location geographically and geologically (along

11220-573: The tree fern Dicksonia , are characteristic of the Antarctic flora. A wide variety of plant life has resided in Antarctica throughout its history. Investigations of Upper Cretaceous and Early Tertiary sediments of Antarctica yield a rich assemblage of well-preserved fossil dicotyledonous angiosperm wood which provides evidence for the existence, since the Late Cretaceous, of temperate forests similar in composition to those found in present-day southern South America, New Zealand and Australia. It

11330-645: The treeline, the conifers give way to Andean scrublands of deciduous Nothofagus antarctica . Northern Patagonian forests . The fourth and last type is the Northern Patagonian forests, which dominate the southern half of the ecoregion, with evergreen species such as the broadleaf Nothofagus dombeyi , Nothofagus betuloides and Drimys winteri and the coniferous podocarps , including Podocarpus nubigenus . Distribution of plants follow Rapoport's rule with plant species distribution increasing at higher latitudes and decreasing at those closer to

11440-617: The tropical latitudes, became hotter and drier, and ultimately connected with the Eurasian continent. Today, the flora of Africa and India have few remnants of the Antarctic flora. Australia drifted north and became drier as well; the humid Antarctic flora retreated to the east coast and Tasmania, while the rest of Australia became dominated by Acacia , Eucalyptus , and Casuarina , as well as xeric shrubs and grasses. Humans arrived in Australia 50–60,000 years ago and used fire to reshape

11550-526: 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. Modern morphology recognises

11660-686: The vegetation of the continent; as a result, the Antarctic flora, also known as the Rainforest flora in Australia, retreated to a few isolated areas composing less than 2% of Australia's land area. The woody plants of the Antarctic flora include conifers in the families Podocarpaceae , Araucariaceae and the subfamily Callitroideae of Cupressaceae , and angiosperms such as the families Proteaceae , Griseliniaceae , Cunoniaceae , Atherospermataceae , and Winteraceae , and genera like southern beech ( Nothofagus ) and fuchsia ( Fuchsia ). Many other families of flowering plants and ferns, including

11770-549: The west coast of southern South America , in Chile and Argentina . It is part of the Neotropical realm . The forests are named after the city of Valdivia . The Valdivian temperate rainforests are characterized by their dense understories of bamboos , ferns , and for being mostly dominated by evergreen angiosperm trees with some deciduous specimens, though conifer trees are also common. Temperate rain forests comprise

11880-485: The word plant (e.g. plant taxonomy, plant ecology, plant anatomy, plant morphology, plant systematics, plant ecology), or prefixing or substituting the prefix phyto- (e.g. phytochemistry , phytogeography ). The study of fossil plants is palaeobotany . Other fields are denoted by adding or substituting the word botany (e.g. systematic botany ). Phytosociology is a subfield of plant ecology that classifies and studies communities of plants. The intersection of fields from

11990-399: 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). 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

12100-412: Was the beginning of popularizing botany to a wider audience. 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

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