Portal:Botany
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Introduction
Botany, also called plant science (or plant sciences), plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek word 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 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 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 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. (Full article...)
Selected general articles
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Image 1In botany, an umbel is an inflorescence that consists of a number of short flower stalks (called pedicels) that spread from a common point, somewhat like umbrella ribs. The word was coined in botanical usage in the 1590s, from Latin umbella "parasol, sunshade". The arrangement can vary from being flat-topped to almost spherical. Umbels can be simple or compound. The secondary umbels of compound umbels are known as umbellules or umbellets. A small umbel is called an umbellule. The arrangement of the inflorescence in umbels is referred to as umbellate, or occasionally subumbellate (almost umbellate).
Umbels are a characteristic of plants such as carrot, parsley, dill, and fennel in the family Apiaceae; ivy, Aralia and Fatsia in the family Araliaceae; and onion (Allium) in the family Alliaceae. (Full article...) -
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Aestivation or estivation is the positional arrangement of the parts of a flower within a flower bud before it has opened. Aestivation is also sometimes referred to as praefoliation or prefoliation, but these terms may also mean vernation: the arrangement of leaves within a vegetative bud.
Aestivation can be an important taxonomic diagnostic; for example Malvaceae flower buds have valvate sepals, with the exception of the genera Fremontodendron and Chiranthodendron, which have sometimes been misplaced as a result. (Full article...) -
Image 3In botany, habit is the general appearance, growth form, or architecture. For example:
- Many species of maple have a shrubby habit and may form bushes or hedges rather than trees.
- Certain alpine plants have been chosen for cultivation because of their dwarf habit.
Plants may be woody or herbaceous. The main types of woody plants are trees, shrubs and lianas. Climbing plants (vines) can be woody (lianas) or herbaceous (nonwoody vines). Plants can also be categorized in terms of their habit as subshrubs (dwarf shrub, bush), cushion plants and succulents. (Full article...) -
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Non-vascular plants are plants without a vascular system consisting of xylem and phloem. Instead, they may possess simpler tissues that have specialized functions for the internal transport of water.
Non-vascular plants include two distantly related groups:- Bryophytes, an informal group that taxonomists now[update] treat as three separate land-plant divisions, namely: Bryophyta (mosses), Marchantiophyta (liverworts), and Anthocerotophyta (hornworts). In all bryophytes, the primary plants are the haploid gametophytes, with the only diploid portion being the attached sporophyte, consisting of a stalk and sporangium. Because these plants lack lignified water-conducting tissues, they cannot become as tall as most vascular plants.
- Algae, especially green algae. The algae consist of several unrelated groups. Only the groups included in the Viridiplantae are still considered relatives of land plants.
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Algae (UK: /ˈælɡiː/ AL-ghee, US: /ˈældʒiː/ AL-jee; sg.: alga /ˈælɡə/ AL-gə) is an informal term for any organisms of a large and diverse group of photosynthetic eukaryotes, which include species from multiple distinct clades. Such organisms range from unicellular microalgae such as Chlorella, Prototheca and the diatoms, to multicellular macroalgae such as the giant kelp, a large brown alga which may grow up to 50 metres (160 ft) in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, Spirogyra and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton.
Algae constitute a polyphyletic group since they do not include a common ancestor, and although their chlorophyll-bearing plastids seem to have a single origin (from symbiogenesis with cyanobacteria), they were acquired in different ways. Green algae are a prominent examples of algae that have primary chloroplasts derived from endosymbiont cyanobacteria. Diatoms and brown algae are examples of algae with secondary chloroplasts derived from endosymbiotic red algae, which they acquired via phagocytosis. Algae exhibit a wide range of reproductive strategies, from simple asexual cell division to complex forms of sexual reproduction via spores. (Full article...) -
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A gametophyte (/ɡəˈmiːtəfaɪt/) is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the sexual phase in the life cycle of plants and algae. It develops sex organs that produce gametes, haploid sex cells that participate in fertilization to form a diploid zygote which has a double set of chromosomes. Cell division of the zygote results in a new diploid multicellular organism, the second stage in the life cycle known as the sporophyte. The sporophyte can produce haploid spores by meiosis that on germination produce a new generation of gametophytes. (Full article...) -
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Phycology (from Ancient Greek φῦκος (phûkos) 'seaweed' and -λογία (-logía) 'study of') is the scientific study of algae. Also known as algology, phycology is a branch of life science.
Algae are important as primary producers in aquatic ecosystems. Most algae are eukaryotic, photosynthetic organisms that live in a wet environment. They are distinguished from the higher plants by a lack of true roots, stems or leaves. They do not produce flowers. Many species are single-celled and microscopic (including phytoplankton and other microalgae); many others are multicellular to one degree or another, some of these growing to large size (for example, seaweeds such as kelp and Sargassum). (Full article...) -
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Cultivated plant taxonomy is the study of the theory and practice of the science that identifies, describes, classifies, and names cultigens—those plants whose origin or selection is primarily due to intentional human activity. Cultivated plant taxonomists do, however, work with all kinds of plants in cultivation.
Cultivated plant taxonomy is one part of the study of horticultural botany which is mostly carried out in botanical gardens, large nurseries, universities, or government departments. Areas of special interest for the cultivated plant taxonomist include: searching for and recording new plants suitable for cultivation (plant hunting); communicating with and advising the general public on matters concerning the classification and nomenclature of cultivated plants and carrying out original research on these topics; describing the cultivated plants of particular regions (horticultural floras); maintaining databases, herbaria and other information about cultivated plants. (Full article...) -
Image 9Evolutionary developmental biology (evo-devo) is the study of developmental programs and patterns from an evolutionary perspective. It seeks to understand the various influences shaping the form and nature of life on the planet. Evo-devo arose as a separate branch of science rather recently. An early sign of this occurred in 1999.
Most of the synthesis in evo-devo has been in the field of animal evolution, one reason being the presence of model systems like Drosophila melanogaster, C. elegans, zebrafish and Xenopus laevis. However, since 1980, a wealth of information on plant morphology, coupled with modern molecular techniques has helped shed light on the conserved and unique developmental patterns in the plant kingdom also. (Full article...) -
Image 10Botanical nomenclature is the formal, scientific naming of plants. It is related to, but distinct from taxonomy. Plant taxonomy is concerned with grouping and classifying plants; botanical nomenclature then provides names for the results of this process. The starting point for modern botanical nomenclature is Linnaeus' Species Plantarum of 1753. Botanical nomenclature is governed by the International Code of Nomenclature for algae, fungi, and plants (ICN), which replaces the International Code of Botanical Nomenclature (ICBN). Fossil plants are also covered by the code of nomenclature.
Within the limits set by that code there is another set of rules, the International Code of Nomenclature for Cultivated Plants (ICNCP) which applies to plant cultivars that have been deliberately altered or selected by humans (see cultigen). (Full article...) -
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The International Code of Nomenclature for algae, fungi, and plants (ICN or ICNafp) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "traditionally treated as algae, fungi, or plants". It was formerly called the International Code of Botanical Nomenclature (ICBN); the name was changed at the International Botanical Congress in Melbourne in July 2011 as part of the Melbourne Code which replaced the Vienna Code of 2005.
The current version of the code is the Shenzhen Code adopted by the International Botanical Congress held in Shenzhen, China, in July 2017. As with previous codes, it took effect as soon as it was ratified by the congress (on 29 July 2017), but the documentation of the code in its final form was not published until 26 June 2018. For fungi the Code was revised by the San Juan Chapter F in 2018. The 2025 edition of ICBN, the Madrid Code, which reflects the decisions of the Twentieth International Botanical Congress met in Madrid, Spain, in July 2024, is prepared to be published in July 2025. (Full article...) -
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Plant ecology is a subdiscipline of ecology that studies the distribution and abundance of plants, the effects of environmental factors upon the abundance of plants, and the interactions among plants 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, and 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 (deserts), Mediterranean ecosystems, temperate forest ecosystems, temperate grasslands, coniferous forests, tundra (both polar and high mountain), 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. (Full article...) -
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The evolution of plants has resulted in a wide range of complexity, from the earliest algal mats of unicellular archaeplastids evolved through endosymbiosis, through multicellular marine and freshwater green algae, to spore-bearing terrestrial bryophytes, lycopods and ferns, and eventually to the complex seed-bearing gymnosperms and angiosperms (flowering plants) of today. While many of the earliest groups continue to thrive, as exemplified by red and green algae in marine environments, more recently derived groups have displaced previously ecologically dominant ones; for example, the ascendance of flowering plants over gymnosperms in terrestrial environments.
There is evidence that cyanobacteria and multicellular thalloid eukaryotes lived in freshwater communities on land as early as 1 billion years ago, and that communities of complex, multicellular photosynthesizing organisms existed on land in the late Precambrian, around 850 million years ago. (Full article...) -
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A stamen typically consists of a stalk called the filament and an anther which contains microsporangia. Most commonly anthers are two-lobed (each lobe is termed a locule) and are attached to the filament either at the base or in the middle area of the anther. The sterile tissue between the lobes is called the connective, an extension of the filament containing conducting strands. It can be seen as an extension on the dorsal side of the anther. A pollen grain develops from a microspore in the microsporangium and contains the male gametophyte. The size of anthers differs greatly, from a tiny fraction of a millimeter in Wolfia spp up to five inches (13 centimeters) in Canna iridiflora and Strelitzia nicolai.
The stamens in a flower are collectively called the androecium. The androecium can consist of as few as one-half stamen (i.e. a single locule) as in Canna species or as many as 3,482 stamens which have been counted in the saguaro (Carnegiea gigantea). The androecium in various species of plants forms a great variety of patterns, some of them highly complex. It generally surrounds the gynoecium and is surrounded by the perianth. A few members of the family Triuridaceae, particularly Lacandonia schismatica and Lacandonia brasiliana, along with a few species of Trithuria (family Hydatellaceae) are exceptional in that their gynoecia surround their androecia. (Full article...) -
Image 15In cell biology, bulk flow is the process by which proteins with a sorting signal [definition needed] travel to and from different cellular compartments. In other words, bulk transport is a type of transport which involves the transport of large amount of substance like lipid droplets and solid food particles across plasma membrane by utilising energy. Special processes are involved in the transport of such large quantities of materials, which include endocytosis and exocytosis.
It is thought that cargo travels through the Golgi cisternae (from cis- to trans- Golgi) via bulk flow. (Full article...) -
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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 slowly, early plant lore usually being treated as part of the study of medicine. Later, classification and description was driven by natural history and natural theology. Until the advent of the theory of evolution, nearly all classification was based on the scala naturae. The professionalization of botany in the 18th and 19th century marked a shift toward more holistic classification methods, eventually based on evolutionary relationships. (Full article...) -
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A botanical name is a formal scientific name conforming to the International Code of Nomenclature for algae, fungi, and plants (ICN) and, if it concerns a plant cultigen, the additional cultivar or Group epithets must conform to the International Code of Nomenclature for Cultivated Plants (ICNCP). The code of nomenclature covers "all organisms traditionally treated as algae, fungi, or plants, whether fossil or non-fossil, including blue-green algae (Cyanobacteria), chytrids, oomycetes, slime moulds and photosynthetic protists with their taxonomically related non-photosynthetic groups (but excluding Microsporidia)."
The purpose of a formal name is to have a single name that is accepted and used worldwide for a particular plant or plant group. For example, the botanical name Bellis perennis denotes a plant species which is native to most of the countries of Europe and the Middle East, where it has accumulated various names in many languages. Later, the plant was introduced worldwide, bringing it into contact with more languages. English names for this plant species include: daisy, English daisy, and lawn daisy. The cultivar Bellis perennis 'Aucubifolia' is a golden-variegated horticultural selection of this species. (Full article...) -
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In botany, a berry is a fleshy fruit without a stone (pit) produced from a single flower containing one ovary. Berries so defined include grapes, currants, and tomatoes, as well as cucumbers, eggplants (aubergines), persimmons and bananas, but exclude certain fruits that meet the culinary definition of berries, such as strawberries and raspberries. The berry is the most common type of fleshy fruit in which the entire outer layer of the ovary wall ripens into a potentially edible "pericarp". Berries may be formed from one or more carpels from the same flower (i.e. from a simple or a compound ovary). The seeds are usually embedded in the fleshy interior of the ovary, but there are some non-fleshy exceptions, such as Capsicum species, with air rather than pulp around their seeds.
Many berries are edible, but others, such as the fruits of the potato and the deadly nightshade, are poisonous to humans. (Full article...) -
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Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or more broadly to include the same type of tissue elsewhere, such as in the roots of trees or shrubs. In a living tree, it performs a mechanical-support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients among the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, woodchips, or fibers.
Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper. More recently it emerged as a feedstock for the production of purified cellulose and its derivatives, such as cellophane and cellulose acetate. (Full article...) -
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Plant anatomy or phytotomy is the general term for the study of the internal structure of plants. Originally, it included plant morphology, the description of the physical form and external structure of plants, but since the mid-20th century, plant anatomy has been considered a separate field referring only to internal plant structure. Plant anatomy is now frequently investigated at the cellular level, and often involves the sectioning of tissues and microscopy. (Full article...) -
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Citrus taxonomy is the botanical classification of the species, varieties, cultivars, and graft hybrids within the genus Citrus and related genera, found in cultivation and in the wild.
Citrus taxonomy is complex and controversial. Cultivated citrus are derived from various citrus species found in the wild. Some are only selections of the original wild types, many others are hybrids between two or more original species, and some are backcrossed hybrids between a hybrid and one of the hybrid's parent species. Citrus plants hybridize easily between species with completely different morphologies, and similar-looking citrus fruits may have quite different ancestries. Some differ only in disease resistance. Conversely, different-looking varieties may be nearly genetically identical, and differ only by a bud mutation. (Full article...) -
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A floral formula is a notation for representing the structure of particular types of flowers. Such notations use numbers, letters and various symbols to convey significant information in a compact form. They may represent the floral form of a particular species, or may be generalized to characterize higher taxa, usually giving ranges of numbers of organs. Floral formulae are one of the two ways of describing flower structure developed during the 19th century, the other being floral diagrams. The format of floral formulae differs according to the tastes of particular authors and periods, yet they tend to convey the same information.
A floral formula is often used along with a floral diagram. (Full article...) -
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Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double sugars, are molecules made of two bonded monosaccharides; common examples are sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (two molecules of glucose). White sugar is a refined form of sucrose. In the body, compound sugars are hydrolysed into simple sugars.
Longer chains of monosaccharides (>2) are not regarded as sugars and are called oligosaccharides or polysaccharides. Starch is a glucose polymer found in plants, the most abundant source of energy in human food. Some other chemical substances, such as ethylene glycol, glycerol and sugar alcohols, may have a sweet taste but are not classified as sugar. (Full article...) -
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Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets, and is contained in large amounts in staple foods such as wheat, potatoes, maize (corn), rice, and cassava (manioc).
Pure starch is a white, tasteless and odorless powder that is insoluble in cold water or alcohol. It consists of two types of molecules: the linear and helical amylose and the branched amylopectin. Depending on the plant, starch generally contains 20 to 25% amylose and 75 to 80% amylopectin by weight. Glycogen, the energy reserve of animals, is a more highly branched version of amylopectin. (Full article...) -
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Bryophytes (/ˈbraɪ.əˌfaɪts/) are a group of land plants (embryophytes), sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants: the liverworts, hornworts, and mosses. In the strict sense, the division Bryophyta consists of the mosses only. Bryophytes are characteristically limited in size and prefer moist habitats although some species can survive in drier environments. The bryophytes consist of about 20,000 plant species. Bryophytes produce enclosed reproductive structures (gametangia and sporangia), but they do not produce flowers or seeds. They reproduce sexually by spores and asexually by fragmentation or the production of gemmae.
Though bryophytes were considered a paraphyletic group in recent years, almost all of the most recent phylogenetic evidence supports the monophyly of this group, as originally classified by Wilhelm Schimper in 1879. (Full article...)
Did you know...
- ... that certain bamboo species release large numbers of seeds in synchrony after numbers of years that have only 2, 3, and 5 as their prime factors?
- ... that despite never having received a formal education in botany, Harry Allan became one of New Zealand's most eminent botanists?
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Selected images
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Image 11 An oat coleoptile with the sun overhead. Auxin (pink) is evenly distributed in its tip.
2 With the sun at an angle and only shining on one side of the shoot, auxin moves to the opposite side and stimulates cell elongation there.
3 and 4 Extra growth on that side causes the shoot to bend towards the sun. (from Botany) -
Image 2A nineteenth-century illustration showing the morphology of the roots, stems, leaves and flowers of the rice plant Oryza sativa (from Botany)
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Image 3Echeveria glauca in a Connecticut greenhouse. Botany uses Latin names for identification; here, the specific name glauca means blue. (from Botany)
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Image 5Micropropagation of transgenic plants (from Botany)
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Image 6The Linnaean Garden of Linnaeus' residence in Uppsala, Sweden, was planted according to his Systema sexuale. (from Botany)
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Image 7The food we eat comes directly or indirectly from plants such as rice. (from Botany)
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Image 8Paper chromatography of some spinach leaf extract shows the various pigments present in their chloroplasts. (from Botany)
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Image 9Thale cress, Arabidopsis thaliana, the first plant to have its genome sequenced, remains the most important model organism. (from Botany)
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Image 10Five of the key areas of study within plant physiology (from Botany)
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Image 11The fruit of Myristica fragrans, a species native to Indonesia, is the source of two valuable spices, the red aril (mace) enclosing the dark brown nutmeg. (from Botany)
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Image 12The nodules of Medicago italica contain the nitrogen fixing bacterium Sinorhizobium meliloti. The plant provides the bacteria with nutrients and an anaerobic environment, and the bacteria fix nitrogen for the plant. (from Botany)
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Plant groups | |||||||||||
Plant anatomy |
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