Botany called plant science, plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist; the term "botany" comes from the Ancient Greek word βοτάνη meaning "pasture", "grass", or "fodder". Traditionally, botany has included the study of fungi and algae by mycologists and phycologists with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress. Nowadays, botanists study 410,000 species of land plants of which some 391,000 species are vascular plants, 20,000 are bryophytes. Botany originated in prehistory as herbalism with the efforts of early humans to identify – and cultivate – edible and poisonous plants, making it one of the oldest branches of science. Medieval physic gardens 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, 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 and differentiation, reproduction and primary metabolism, chemical products, diseases, evolutionary relationships 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, rubber and drugs, in modern horticulture and forestry, plant propagation and genetic modification, in the synthesis of chemicals and raw materials for construction and energy production, in environmental management, the maintenance of biodiversity. Botany originated as the study and use of plants for their medicinal properties. Many records of the Holocene period date early botanical knowledge as far back as 10,000 years ago; 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. 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, in archaic Avestan writings, in works from China before it was unified in 221 BC.
Modern botany traces its roots back to Ancient Greece to Theophrastus, a student of Aristotle who invented and described many of its principles and is 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 seventeen centuries later. 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 read for more than 1,500 years. Important contributions from the medieval Muslim world include Ibn Wahshiyya's Nabatean Agriculture, Abū Ḥanīfa Dīnawarī's the Book of Plants, Ibn Bassal's The Classification of Soils. In the early 13th century, Abu al-Abbas al-Nabati, Ibn al-Baitar 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 considered to be the first, still in its original location.
These gardens continued the practical value of earlier "physic gardens" 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 to northern Europe. Throughout this period, botany remained subordinate to medicine. German physician Leonhart Fuchs was one of "the three German fathers of botany", along with theologian Otto Brunfels and physician Hieronymus Bock. 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 authored a botanically and pharmacologically important herbal Historia Plantarum in 1544 and a pharmacopoeia of lasting importance, the Dispensatorium
Germination is the process by which an organism grows from a seed or similar structure. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. In addition, the growth of a sporeling from a spore, such as the spores of hyphae from fungal spores, is germination. Thus, in a general sense, germination can be thought of as anything expanding into greater being from a small existence or germ. Most seeds do not need sunlight to germinate but some seeds such as sunflower seeds, mustard seeds and blosnian seeds need sunlight to germinate. Experiments were carried out to prove this. Germination is the growth of a plant contained within a seed; the seed of a vascular plant is a small package produced in a fruit or cone after the union of male and female reproductive cells. All developed seeds contain an embryo and, in most plant species some store of food reserves, wrapped in a seed coat; some plants produce varying numbers of seeds. Dormant seeds are ripe seeds that do not germinate because they are subject to external environmental conditions that prevent the initiation of metabolic processes and cell growth.
Under proper conditions, the seed begins to germinate and the embryonic tissues resume growth, developing towards a seedling. Seed germination depends on both external conditions; the most important external factors include right temperature, oxygen or air and sometimes light or darkness. Various plants require different variables for successful seed germination; this depends on the individual seed variety and is linked to the ecological conditions of a plant's natural habitat. For some seeds, their future germination response is affected by environmental conditions during seed formation. Water is required for germination. Mature seeds are extremely dry and need to take in significant amounts of water, relative to the dry weight of the seed, before cellular metabolism and growth can resume. Most seeds need enough water to moisten the seeds but not enough to soak them; the uptake of water by seeds is called imbibition, which leads to the swelling and the breaking of the seed coat. When seeds are formed, most plants store a food reserve with the seed, such as starch, proteins, or oils.
This food reserve provides nourishment to the growing embryo. When the seed imbibes water, hydrolytic enzymes are activated which break down these stored food resources into metabolically useful chemicals. After the seedling emerges from the seed coat and starts growing roots and leaves, the seedling's food reserves are exhausted. Oxygen is required by the germinating seed for metabolism. Oxygen is used in aerobic respiration, the main source of the seedling's energy until it grows leaves. Oxygen is an atmospheric gas, found in soil pore spaces; some seeds have impermeable seed coats that prevent oxygen from entering the seed, causing a type of physical dormancy, broken when the seed coat is worn away enough to allow gas exchange and water uptake from the environment. Temperature affects cellular growth rates. Seeds from different species and seeds from the same plant germinate over a wide range of temperatures. Seeds have a temperature range within which they will germinate, they will not do so above or below this range.
Many seeds germinate at temperatures above 60-75 F, while others germinate just above freezing and others germinate only in response to alternations in temperature between warm and cool. Some seeds germinate when the soil is cool 28-40 F, some when the soil is warm 76-90 F; some seeds require exposure to cold temperatures to break dormancy. Some seeds in a dormant state will not germinate if conditions are favorable. Seeds that are dependent on temperature to end dormancy have a type of physiological dormancy. For example, seeds requiring the cold of winter are inhibited from germinating until they take in water in the fall and experience cooler temperatures. Cold stratification is a process that induces the dormancy breaking prior to light emission that promotes germination. Four degrees Celsius is cool enough to end dormancy for most cool dormant seeds, but some groups within the family Ranunculaceae and others, need conditions cooler than -5 C; some seeds will only germinate after hot temperatures during a forest fire which cracks their seed coats.
Most common annual vegetables have optimal germination temperatures between 75-90 F, though many species can germinate at lower temperatures, as low as 40 F, thus allowing them to be grown from seeds in cooler climates. Suboptimal temperatures lead to longer germination periods. Light or darkness can be an environmental trigger for germination and is a type of physiological dormancy. Most seeds are not affected by light or darkness, but many seeds, including species found in forest settings, will not germinate until an opening in the canopy allows sufficient light for growth of the seedling. Scarification mimics natural processes that weaken the seed coat before ger
Pyrus pyrifolia is a species of pear tree native to East Asia. The tree's edible fruit is known by many names, including: Asian pear, Chinese pear, Korean pear, Japanese pear, Taiwanese pear, zodiac pear, sand pear. Along with cultivars of P. × bretschneideri and P. ussuriensis, the fruit is called the nashi pear. Cultivars derived from Pyrus pyrifolia are grown throughout East Asia, in other countries such as India, New Zealand, the United States. Traditionally in East Asia the tree's flowers are a popular symbol of early spring, it is a common sight in gardens and the countryside; the fruits are not baked in pies or made into jams because they have a high water content and a crisp, grainy texture different from the European varieties. They are served raw and peeled; the fruit tends to be quite large and fragrant, when wrapped, it can last for several weeks or more in a cold, dry place. Due to their high price and the large size of the fruit of cultivars, the pears tend to be served to guests, given as gifts, or eaten together in a family setting.
In cooking, ground pears are used in vinegar- or soy sauce-based sauces as a sweetener, instead of sugar. They are used when marinating meat beef. In Korea, the fruit is known as bae, it is grown and consumed in great quantity. In the South Korean city of Naju, there is a museum called The Naju Pear Museum and Pear Orchard for Tourists. In Australia, these pears were first introduced into commercial production beginning in 1980. In Japan, fruit is harvested in Chiba, Tottori, Tochigi, Niigata and other prefectures, except Okinawa. Nashi may be used as "season word", when writing haiku. Nashi no hana is used as a kigo of spring. At least one city has the flowers of this tree as an official city flower. In Nepal and the Himalayan states of India, they are cultivated as a cash crop in the Middle Hills between about 1,500 and 2,500 meters’ elevation where the climate is suitable; the fruit are carried to nearby markets by human porters or by truck, but not for long distances because they bruise easily.
In Taiwan, pears harvested in Japan have become luxurious presents since 1997 and their consumption has jumped. In China, the term "sharing a pear" is a homophone of "separate", as a result, sharing a pear with a loved one can be read as a desire to separate from them. In Cyprus, the pears were introduced in 2010 after being investigated as a new fruit crop for the island in the early 1990s, they are grown in Kyperounta. Cultivars are classified in two groups. Most of the cultivars belong to the Akanashi group, have yellowish-brown rinds; the Aonashi have yellow-green rinds. Important cultivars include:'Chojuro"Kosui','Hosui"Imamuraaki"Nijisseiki"Niitaka"Okusankichi"Raja"Shinko"Hwangkeum"Huanghuali' Guidelines for the conduct of tests for distinctness and stability - Japanese pear, The International Union for the Protection of New Varieties of Plants, 1994-11-04. ニホンナシ育成品種の系統図, National Institute of Fruit Tree Science, Japan Shin Hiratsuka, Shao-Ling Zhang "Relationships between fruit set, pollen-tube growth, S-RNase concentration in the self-incompatible Japanese pear" Scientia Horticulturae, 95, 309-318.
Carlos Castillo, Takeshi Takasaki, Toshihiro Saito, Shigemi Norioka, Tetsu Nakanishi "Clonlng of the S8-RNase of Japanese Pear" Plant Biotechnology, 19, 1-6
Plant ecology is a subdiscipline of ecology which studies the distribution and abundance of plants, the effects of environmental factors upon the abundance of plants, the interactions among and between plants and other organisms. Examples of these are the distribution of temperate deciduous forests in North America, the effects of drought or flooding upon plant survival, competition among desert plants for water, or effects of herds of grazing animals upon the composition of grasslands. A global overview of the Earth's major vegetation types is provided by O. W. Archibold, he recognizes 11 major vegetation types: tropical forests, tropical savannas, arid regions, Mediterranean ecosystems, temperate forest ecosystems, temperate grasslands, coniferous forests, terrestrial wetlands, freshwater ecosystems and coastal/marine systems. This breadth of topics shows the complexity of plant ecology, since it includes plants from floating single-celled algae up to large canopy forming trees. One feature that defines plants is photosynthesis.
Photosynthesis is the process of a chemical reactions to create glucose and oxgyen, vital for plant life. One of the most important aspects of plant ecology is the role plants have played in creating the oxygenated atmosphere of earth, an event that occurred some 2 billion years ago, it can be dated by the deposition of banded iron formations, distinctive sedimentary rocks with large amounts of iron oxide. At the same time, plants began removing carbon dioxide from the atmosphere, thereby initiating the process of controlling Earth's climate. A long term trend of the Earth has been toward increasing oxygen and decreasing carbon dioxide, many other events in the Earth's history, like the first movement of life onto land, are tied to this sequence of events. One of the early classic books on plant ecology was written by J. E. Weaver and F. E. Clements, it talks broadly about plant communities, the importance of forces like competition and processes like succession. Plant ecology can be divided by levels of organization including plant ecophysiology, plant population ecology, community ecology, ecosystem ecology, landscape ecology and biosphere ecology.
The study of plants and vegetation is complicated by their form. First, most plants are rooted in the soil, which makes it difficult to observe and measure nutrient uptake and species interactions. Second, plants reproduce vegetatively, asexually, in a way that makes it difficult to distinguish individual plants. Indeed, the concept of an individual is doubtful, since a tree may be regarded as a large collection of linked meristems. Hence, plant ecology and animal ecology have different styles of approach to problems that involve processes like reproduction and mutualism; some plant ecologists have placed considerable emphasis upon trying to treat plant populations as if they were animal populations, focusing on population ecology. Many other ecologists believe that while it is useful to draw upon population ecology to solve certain scientific problems, plants demand that ecologists work with multiple perspectives, appropriate to the problem, the scale and the situation. Plant ecology has its origin in the application of plant physiology to the questions raised by plant geographers.
Carl Ludwig Willdenow was one of the first to note that similar climates produced similar types of vegetation when they were located in different parts of the world. Willdenow's student, Alexander von Humboldt, used physiognomy to describe vegetation types and observed that the distribution vegetation types was based on environmental factors. Plant geographers who built upon Humboldt's work included Joakim Frederik Schouw, A. P. de Candolle, August Grisebach and Anton Kerner von Marilaun. Schouw's work, published in 1822, linked plant distributions to environmental factors and established the practice of naming plant associations by adding the suffix -etum to the name of the dominant species. Working from herbarium collections, De Candolle searched for general rules of plant distribution and settled on using temperature as well. Grisebach's two-volume work, Die Vegetation der Erde nach Ihrer Klimatischen Anordnung, published in 1872, saw plant geography reach its "ultimate form" as a descriptive field.
Starting in the 1870s, Swiss botanist Simon Schwendener, together with his students and colleagues, established the link between plant morphology and physiological adaptations, laying the groundwork for the first ecology textbooks, Eugenius Warming's Plantesamfund and Andreas Schimper's 1898 Pflanzengeographie auf Physiologischer Grundlage. Warming incorporated plant morphology, physiology taxonomy and biogeography into plant geography to create the field of plant ecology. Although more morphological than physiological, Schimper's has been considered the beginning of plant physiological ecology. Plant ecology was built around static ideas of plant distribution. Henry Chandler Cowles' studies of plant succession on the Lake Michigan sand dunes and Frederic Clements' 1916 monograph on the subject established it as a key element of plant ecology. Plant ecology developed within the wider discipline of ecology over the twentieth century. Inspired by Warming's Plantesamfund, Arthur Tansley set out to map British plant communities.
In 1904 he teamed up with William Gardner Smith and others involved in vegetation mapping to establish the Central Committee for the Survey and Study of British Vegetation shortened to British Vegetation Committee. In 1913, the British Vegetation Committee organised the British Ecological
History of plant systematics
The history of plant systematics—the biological classification of plants—stretches from the work of ancient Greek to modern evolutionary biologists. As a field of science, plant systematics came into being only early plant lore being treated as part of the study of medicine. 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 based on evolutionary relationships; the Sushrut first classify plant in 4 categories on basis of flowering pattern structure and life span. Vanspataya Vruksha Virudh Aushodh तासां स्थावराश्चतुर्विधाः- वनस्पतयो, वृक्षा, वीरुध, ओषधय इति | तासु, अपुष्पाः फलवन्तो वनस्पतयः, पुष्पफलवन्तो वृक्षाः, प्रतानवत्यः स्तम्बिन्यश्च वीरुधः, फलपाकनिष्ठा ओषधय इति ||Sushrut Sutra 1/21|| <<https://en.wikipedia.org/wiki/Sushruta>> The peripatetic philosopher Theophrastus, as a student of Aristotle in Ancient Greece, wrote Historia Plantarum, the earliest surviving treatise on plants, where he listed the names of over 500 plant species.
He did not articulate a formal classification scheme, but relied on the common groupings of folk taxonomy combined with growth form: tree shrub. The De Materia Medica of Dioscorides was an important early compendium of plant descriptions, classifying plants chiefly by their medicinal effects. In the 16th century, works by Otto Brunfels, Hieronymus Bock, Leonhart Fuchs helped to revive interest in natural history based on first-hand observation. With the influx of exotic species in the Age of Exploration, the number of known species expanded but most authors were far more interested in the medicinal properties of individual plants than an overarching classification system. Influential Renaissance books include those of Caspar Bauhin and Andrea Cesalpino. 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. Ray, who listed over 18,000 plant species in his works, is credited with establishing the monocot/dicot division and some of his groups — mustards, mints and grasses — stand today. Tournefort used an artificial system based on logical division, 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 by Linnaeus. It presented a complete list of the plant species 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; the consistent use of binomial nomenclature along with a complete listing of all plants provided a huge stimulus for the field.
Although meticulous, the classification of Linnaeus served as an identification manual. It assumed that plant species were given by God and that what remained for humans was to recognise them and use them. 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. Significant contributions to plant classification came from de Jussieu 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, resulting in the aim to group plants by their phylogenetic relationships. To this was added the interest in plant anatomy, aided by the use of the light microscope and the rise of chemistry, allowing the analysis of secondary metabolites; the strict use of epithets in botany, although regulated by international codes, is considered unpractical and outdated.
The notion of species, the fundamental classification unit, is up to subjective intuition and thus can not be well defined. As a result, estimate of the total number of existing "species" 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 consolidated molecular phylogenetics as the best available method. For the first time relatedness could be measured in real terms, namely similarity of the m
Ethnobotany is the study of a region's plants and their practical uses through the traditional knowledge of a local culture and people. An ethnobotanist thus strives to document the local customs involving the practical uses of local flora for many aspects of life, such as plants as medicines and clothing. Richard Evans Schultes referred to as the "father of ethnobotany", explained the discipline in this way: Ethnobotany means... investigating plants used by societies in various parts of the world. Since the time of Schultes, the field of ethnobotany has grown from acquiring ethnobotanical knowledge to that of applying it to a modern society in the form of pharmaceuticals. Intellectual property rights and benefit-sharing arrangements are important issues in ethnobotany; the idea of ethnobotany was first proposed by the early 20th century botanist John William Harshberger. While Harshberger did perform ethnobotanical research extensively, including in areas such as North Africa, Mexico and Pennsylvania, it was not until Richard Evans Schultes began his trips into the Amazon that ethnobotany become a more well known science.
However, the practice of ethnobotany is thought to have much earlier origins in the first century AD when a Greek physician by the name of Pedanius Dioscorides wrote an extensive botanical text detailing the medical and culinary properties of "over 600 mediterranean plants" named De Materia Medica. Historians note that Dioscorides wrote about traveling throughout the Roman empire, including regions such as "Greece, Crete and Petra", in doing so obtained substantial knowledge about the local plants and their useful properties. European botanical knowledge drastically expanded once the New World was discovered due to ethnobotany; this expansion in knowledge can be attributed to the substantial influx of new plants from the Americas, including crops such as potatoes, peanuts and tomatoes. One French explorer in the 16th century, Jacques Cartier, learned a cure for scurvy from a local Iroquois tribe. During the medieval period, ethnobotanical studies were found connected with monasticism. Notable at this time was Hildegard von Bingen.
However, most botanical knowledge was kept in gardens such as physic gardens attached to hospitals and religious buildings. It was thought of in practical use terms for culinary and medical purposes and the ethnographic element was not studied as a modern anthropologist might approach ethnobotany today. Carl Linnaeus carried out in 1732 a research expedition in Scandinavia asking the Sami people about their ethnological usage of plants; the age of enlightenment saw a rise in economic botanical exploration. Alexander von Humboldt collected data from the New World, James Cook's voyages brought back collections and information on plants from the South Pacific. At this time major botanical gardens were started, for instance the Royal Botanic Gardens, Kew in 1759; the directors of the gardens sent out gardener-botanist explorers to care for and collect plants to add to their collections. As the 18th century became the 19th, ethnobotany saw expeditions undertaken with more colonial aims rather than trade economics such as that of Lewis and Clarke which recorded both plants and the peoples encountered use of them.
Edward Palmer collected material culture artifacts and botanical specimens from people in the North American West and Mexico from the 1860s to the 1890s. Through all of this research, the field of "aboriginal botany" was established—the study of all forms of the vegetable world which aboriginal peoples use for food, textiles and more; the first individual to study the emic perspective of the plant world was a German physician working in Sarajevo at the end of the 19th century: Leopold Glück. His published work on traditional medical uses of plants done by rural people in Bosnia has to be considered the first modern ethnobotanical work. Other scholars analyzed uses of plants under an indigenous/local perspective in the 20th century: Matilda Coxe Stevenson, Zuni plants. In the beginning, ethonobotanical specimens and studies were not reliable and sometimes not helpful; this is because the anthropologists did not always collaborate in their work. The botanists focused on identifying species and how the plants were used instead of concentrating upon how plants fit into people's lives.
On the other hand, anthropologists were interested in the cultural role of plants and treated other scientific aspects superficially. In the early 20th century and anthropologists better collaborated and the collection of reliable, detailed cross-disciplinary data began. Beginning in the 20th century, the field of ethnobotany experienced a shift from the raw compilation of data to a greater methodological and conceptual reorientation; this is the beginning of academic ethnobotany. The so-called "father" of this discipline is Richard Evans Schultes though he did not coin the term "ethnobotany". Today the field of ethnobotany requires a variety of skills: botanical training for the identification and preservation of plant specimens. Mark Plotkin, who studied at Harvard University, the Yale School of Forestry and Tufts University, has contributed a number of books on ethnobotany, he completed a
Bracken is a genus of large, coarse ferns in the family Dennstaedtiaceae. Ferns are vascular plants that have alternating generations, large plants that produce spores and small plants that produce sex cells. Brackens are noted for their large divided leaves, they are found on all continents except Antarctica and in all environments except deserts, though their typical habitat is moorland. The genus has the widest distribution of any fern in the world. In the past, the genus was treated as having only one species, Pteridium aquilinum, but the recent trend is to subdivide it into about ten species. Like other ferns, brackens do not have seeds or fruits, but the immature fronds, known as fiddleheads, are sometimes eaten, although some are thought to be carcinogenic; the word bracken is of Old Norse origin, related to Swedish bräken and Danish bregne, both meaning fern. Evolutionarily, bracken may be considered one of the most successful ferns. Bracken, like heather, is found in moorland environments, is referred to by local populations in the north of England as'Moorland Scrub'.
It is one of the oldest ferns, with fossil records over 55 million years old having been found. The plant sends up large, triangular fronds from a wide-creeping underground rootstock, may form dense thickets; this rootstock may travel a metre or more underground between fronds. The fronds may grow up to 2.5 m long or longer with support, but are in the range of 0.6–2 m high. In cold environments, bracken is deciduous and, as it requires well-drained soil, is found growing on the sides of hills. Fern spores are contained in structures found on the underside of the leaf called sori; the linear, leaf-edge pattern of these in bracken is different from that in most other ferns, where the sori are circular and occur towards the centre of the leaf. Pteridium aquilinum is the most common species with a cosmopolitan distribution, occurring in temperate and subtropical regions throughout much of the world, it is a prolific and abundant plant in the moorlands of Great Britain, where it is limited to altitudes of below 600 metres.
It does not like poorly drained fen. It has been observed growing in soils from pH 2.8 to 8.6. Exposure to cold or high pH inhibits its growth, it causes such a problem of invading pastureland that at one time the British government had an eradication programme. Special filters have been used on some British water supplies to filter out the bracken spores. NBN distribution map for the United Kingdom Bracken is a characteristic moorland plant in the UK which over the last decades has out-competed characteristic ground-cover plants such as moor grasses, cowberry and heathers and now covers a considerable part of upland moorland. Once valued and gathered for use in animal bedding, tanning and glass making and as a fertiliser, bracken is now seen as a pernicious and opportunistic plant, taking over from the plants traditionally associated with open moorland and reducing easy access by humans, it is toxic to cattle, sheep and horses and is linked to cancers in humans. It can harbour high levels of sheep ticks.
Grazing provided some control by stock trampling, but this has ceased since the 2007 foot-and-mouth disease outbreak reduced commercial livestock production. Global climatic changes have suited bracken well and contributed to its rapid increase in land coverage. Bracken is a well-adapted pioneer plant which can colonise land with the potential to extend its area by as much as 1–3% per year; this ability to expand is at the expense of other plants and wildlife, can cause major problems for land users and managers. It colonises ground with an open vegetation structure but is slow to colonise healthy, well managed heather stands. Bracken presents a threat to biodiversity. Many species occur only on upland moorland, tied to features unique to the habitat; the loss and degradation of such areas due to the dominance of bracken has caused many species to become rare and isolated. Species Woodland fungi such as Mycena epipterygia can be found growing under the bracken canopy. Both Camarographium stephensii and Typhula quisquiliaris grow from dead bracken stems.
Bracken fern is known to produce and release allelopathic chemicals, an important factor in its ability to dominate other vegetation in regrowth after fire. Its chemical emissions, shady canopy and thick litter inhibit other plant species from establishing themselves – with the occasional exception of plants which support rare butterflies. Herb and tree seedling growth may be inhibited after bracken fern is removed because active plant toxins remain in the soil. Brackens substitute the characteristics of a woodland canopy, are important for giving shade to European plants such as common bluebell and wood anemone where the woodland does not exist; these plants are intolerant to stock trampling. Dead bracken provides a warm microclimate for development of the immature stages. Climbing corydalis, wild gladiolus and chickweed wintergreen seem to benefit from the conditions found under bracken stands; the high humidity helps mosses survive underneath, including Campylopus flexuosus, Hypnum cupressiforme, Polytrichum commune, Pseudoscelopodium purum and Rhytidiadelphus squarrosus.
Brackens of the Northern Hemisphere are used as food plants by the larvae of some Lepidoptera species including dark green fritillary, dot moth, high brown fritillary, gold swift, map-winged swift, pearl-bordered fritillary, orange swift, small angle shades, small pearl-bordered fritillary. They form an i