Misplaced Pages

#527472

101-519: Fronds have particular terms describing their components. Like all leaves, fronds usually have a stalk connecting them to the main stem. In botany , this leaf stalk is generally called a petiole , but in regard to fronds specifically it is called a stipe , and it supports a flattened blade (which may be called a lamina), and the continuation of the stipe into this portion is called the rachis . The blades may be simple (undivided), pinnatifid (deeply incised, but not truly compound), pinnate (compound with

202-490: 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

303-414: 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

404-452: 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

505-452: A frond is divided once into pinnae, the frond is called once pinnate. In some fronds the pinnae are further divided into segments, creating a bipinnate frond. The segments into which each pinna are divided are called pinnules, and the extensions of the rachis that support these pinnules, are called rachillae. Rarely, a frond may even be tripinnate, in which case the pinnule divisions are known as ultimate segments. Pinnae may be arranged along

606-400: 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

707-404: 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

808-552: 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

909-464: 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

1010-505: 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

1111-536: 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

SECTION 10

#1732773266528

1212-460: 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

1313-1010: 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

1414-628: 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 ,

1515-456: 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

1616-406: 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)

1717-405: Is Hishimonus phycitis , which transmits the phytoplasma-caused little leaf phyllody in eggplants . The broken-backed bug ( Taylorilygus apicalis ) is another insect vector of a phytoplasma-caused phyllody in species of Parthenium . Other ectoparasite vectors include eriophyid mites , like the rose leaf curl mite ( Phyllocoptes fructiplilus ) which is known to be the primary vector of

1818-405: 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

1919-481: 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

2020-476: 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

2121-502: Is a magic flower in Polish folklore. As ferns are non-flowering plants, this technically refers to "fertile fronds". Certain true ferns, e.g., Osmunda regalis have sporangia in tight clusters which may appear flower-like. Botany 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

SECTION 20

#1732773266528

2222-402: Is an outgrowth of the blade surface that may partly cover the sporangia. Some fern species feature frond dimorphism , in which fertile and sterile fronds differ in appearance and structure. Fern fronds, as with all leaves, arise from the stem, either directly, or on an outgrowth from the stem termed a phyllopodium . The stem of a typical (leptosporangiate) fern is subterranean or horizontal on

2323-438: Is characterized by the partial or complete replacement of floral organs with true leaves. Phyllody can affect bracts , the calyx ( sepals ), corolla ( petals ), the gynoecium ( carpels / pistils ), and the androecium ( stamens ). Phyllody may be partial, affecting only some sets of floral organs or even only half of a set of floral organs (e.g. only three petals out of six in a single flower); or it can be complete, with all

2424-762: 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

2525-439: Is generally caused by phytoplasma or virus infections, though it may also be because of environmental factors that result in an imbalance in plant hormones . Phyllody causes the affected plant to become partially or entirely sterile, as it is unable to produce normal flowers . The condition is also known as phyllomorphy or frondescence ; though the latter may sometimes refer more generically to foliage, leafiness, or

2626-433: Is more common among flowers that have united sepals ( monosepalous ) than in flowers with separated sepals ( polysepalous ). Phyllody of the petals can be expressed more mildly as a simple change in shape and color (in which case, it's more accurately virescence ), or it can be expressed as fully formed leaves. It is more common among flowers which exhibit corollas of distinct petals ( polypetalous ) than in flowers in which

2727-531: Is now known to be essentially correct. The concepts he discusses while describing metamorphosis is now known as homology , the basis of the modern science of comparative anatomy and a discovery that is usually credited to the English biologist Sir Richard Owen . In 1832, the German- American botanist George Engelmann described the same condition in his work De Antholysi Prodromus . He gave it

2828-451: 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

2929-400: 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

3030-444: 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

3131-498: 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

Frond - Misplaced Pages Continue

3232-777: Is usually called phyllody . The palm frond has been a symbol of victory, triumph, peace, and eternal life originating in the ancient Mediterranean world. For example, in some Christian traditions, during Palm Sunday, Jesus’ entrance into Jerusalem is celebrated by carrying palm leaves. During the Victorian phenomenon of Pteridomania or "fern craze", fern fronds became wildly popular symbols. Because fronds are somewhat flat, they could be used for decoration in ways that many other plants could not be. They were glued into collectors' albums, affixed to three dimensional objects, used as stencils for "spatter-work", inked and pressed into surfaces for nature printing, and so forth. The fern flower

3333-564: 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

3434-499: 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

3535-417: 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

3636-504: 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,

3737-565: 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

3838-626: 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

3939-444: 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

4040-427: 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

4141-426: 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

Frond - Misplaced Pages Continue

4242-408: 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 ,

4343-517: 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

4444-482: 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

4545-412: 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

4646-439: 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

4747-530: The application of gibberellins (GA), plant hormones responsible for stem elongation, flowering , and sex expression . Other related floral development abnormalities are: In some cases, the occurrence of phyllody has been utilized in plant breeding . One of the most well known examples is the green rose ( Rosa chinensis 'Viridiflora'), an ancient Chinese rose cultivar which exhibits green leafy bracts in tight flower-like clusters. In green rose, artificial selection has enabled phyllody to be expressed as

4848-447: 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

4949-500: 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 ,

5050-446: 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)

5151-812: The carpels can become leaf-like (although the distal half of the style and the stigma are usually unaffected). Incidentally, some Japanese cherry cultivars also exhibit "doubling" of the petals due to petalody, where a second corolla develops instead of stamens. In many cultivated plants, phyllody is caused by infections of plant pathogens and/or infestations of ectoparasites . Aside from exhibiting phyllody, they may also exhibit other symptoms like virescence , witch's brooms , chlorosis , and stunted growth. Examples of these biotic factors include: In addition to causing phyllody itself, insects and other ectoparasites also serve as disease vectors that can spread phyllody to other nearby plants. The most common of these insect vectors are leafhoppers , an example of which

SECTION 50

#1732773266528

5252-513: 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 ,

5353-461: 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

5454-463: 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

5555-464: The early growth stages, these organs can develop into something other than the original "plan of construction". He called this abnormal growth "metamorphosis" and it is the main topic of his essay Versuch die Metamorphose der Pflanzen zu erklären (1790), better known in English as the Metamorphosis of Plants . Goethe's hypothesis was poorly received by other scientists during his time, but it

5656-419: 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

5757-427: The entire bodies of thalloid organisms, or the superficially leaf-like structures developed by some animals and fungi. Examples include frondose colonial bryozoans , extinct Ediacaran biota such as rangeomorphs , and some macroalgae and lichens. In paleontology of Ediacaran marine organisms, a frond may be defined as "a rangeomorph unit with a growth tip that can generate primary branches". A frond may also refer to

5858-447: The entire frondose organism, including any stem or basal disc. To classify rangeomorph taxa, the frond is generally subdivided into segments as are those of a fern, and categorized by six factors: polarity, rows of branches, inflation, display/furling, alignment of branches, and presence of a basal disc. Frondescence is the production of leaves; it can also refer to the abnormal development of floral parts into leafy structures, though this

5959-453: 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

6060-670: The floral organs replaced by leaves. Phyllody of the bracts is common among plants which bear catkin ( amentaceous ) inflorescences. They are very common among members of the genus Plantago , for example, as well as the common hop ( Humulus lupulus ). Involucral bracts of the flowers of members of the family Asteraceae like dahlias and dandelions , may also be affected. Sepals that exhibit phyllody are usually hard to detect due to fact that most sepals already resemble leaves. Close examination, however, can reveal differences in venation in normal sepals and sepals that exhibit phyllody. The full development of perfect leaves from sepals

6161-575: 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

SECTION 60

#1732773266528

6262-451: 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

6363-420: 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. Phyllody Phyllody is the abnormal development of floral parts into leafy structures. It

6464-444: 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

6565-458: The group Ophioglossales have a unique arrangement -- such as a single fleshy or amorphous leaf. Fern fronds often bear sporangia , where the plant's spores are formed, usually on the underside (abaxial surface) of the pinnae, but sometimes marginally or scattered over the frond. The sporangia are typically clustered into a sorus (pl., sori). Associated with each sorus in many species is a membranous protective structure called an indusium, which

6666-621: 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

6767-478: 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

6868-532: The late 18th century, the German poet and philosopher Johann Wolfgang von Goethe noted strange-looking rose flowers where the flower organs were replaced by leafy or stem-like structures. This led him to hypothesize that plant organs arising from the stem are simply modifications of the same basic leaf organ. During growth, these organs naturally differentiate into specialized or generalized structures like petals or leaves. However, if certain factors interfere during

6969-403: 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

7070-576: 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

7171-414: The leaflets arranged along a rachis to resemble a feather), or further compound (subdivided). If compound, a frond may be compound once, twice, or more. In a frond which is pinnate (feather-shaped), each leafy segment of the blade is called a pinna (plural pinnae), the stalk bearing the pinna is termed a petiolule, and the main vein or mid-rib of the pinna is referred to as a costa (plural costae). If

7272-576: 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),

7373-493: 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

7474-474: 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

7575-488: The name "frondescence". Nineteen years later, the Belgian botanist Charles Jacques Édouard Morren also investigated the phenomenon in his book Lobelia (1851). Morren called the condition "phyllomorphy", and unlike Engelmann, Morren explicitly distinguished phyllomorphy (wherein the floral parts are replaced by leaf-like structures) from virescence (wherein the affected parts, not necessarily floral, turn green but retain

7676-596: 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

7777-480: The original form or structure). The term "phyllody" was coined by the English botanist Maxwell T. Masters in his book on plant abnormalities, Vegetable Teratology (1869). The term is derived from Scientific Latin phyllodium , which is itself derived from Ancient Greek φυλλώδης ( phullodes , 'leaf-like'). Like Morren, Masters also distinguished phyllody from virescence . He acknowledged "frondescence" and "phyllomorphy" as synonyms of phyllody. Phyllody

7878-447: 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

7979-404: 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

8080-791: 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

8181-541: The palm of a hand and have a short midrib or costa. Palmate fronds are also shaped like the palm of the hand, but all ribs or leaflets arise from a central area. A hastula is a flap of tissue borne at the insertion of the blade on the petiole on the upper, lower, or both leaf surfaces Bifurcate fronds may also develop. The extinct Devonian seed plant Cosmosperma polyloba demonstrated the early evolutionary diversification of frond branching patterns, presenting both bifurcate and trifurcate types. Some ferns, like members of

8282-432: The petals are fused into a single tube or bowl-like structure ( monopetalous ). Phyllody of the stamens is rare. In fact, the stamens are the least likely of the floral organs to be affected by phyllody. This is thought to be because the stamens are the most highly differentiated organs in flowers. In contrast, phyllody of the carpels is much more common than the corresponding changes in stamens. Usually, phyllody affects

8383-490: 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

8484-486: 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

8585-442: 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

8686-556: 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)

8787-562: The process of leaf growth. Phyllody is usually differentiated from floral virescence , wherein the flowers merely turn green in color but otherwise retain their normal structure. However, floral virescence and phyllody (along with witch's broom and other growth abnormalities), commonly occur together as symptoms of the same diseases. The term chloranthy is also often used for phyllody (particularly flowers exhibiting complete phyllody, such that it resembles leaf buds more than flowers), though in some cases it may refer to floral virescence. In

8888-492: The proximal parts of the carpel (the ovary) more than the distal parts (the style and stigma ). The ovule itself may be exposed on the edges or on the inner surface of the carpel if the ovary becomes leaf-like. If the ovule is affected by phyllody, it develops separately from the rest of the carpel. The best known example of phyllody of the carpels is found in the Japanese cherry ( Prunus serrulata ), in which one or both of

8989-462: The rachis either directly opposite one another or alternating up the stem. The arrangement may change from the base of a blade to the tip, as in the example of Blechnum shown below (from base to tip: pinnae opposite to alternate, and pinnatisect to pinnatifid). Some fronds are not pinnately compound (or simple), but may be palmate , costapalmate, or bifurcate . There is a spectrum from costapalmate to palmate. Costapalmate fronds are shaped like

9090-461: 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

9191-404: The rose rosette disease; and the chrysanthemum rust mite ( Paraphytoptus chrysanthemi ) which transmits phytoplasma-caused phyllody in species of chrysanthemums . Environmental abiotic factors like hot weather or water stress that result in an imbalance in plant hormones during flowering can cause phyllody. These can usually be differentiated from phyllody caused by biotic factors by

9292-680: 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

9393-426: The simultaneous presence of healthy and abnormal flowers. When conditions normalize, the plants resume normal flowering. The susceptibility of plants to environmentally caused phyllody can be genetic. Phyllody can be artificially induced by applying cytokinins (CK), plant hormones responsible for cell division, as well as apical dominance and axillary bud growth. Conversely, it can be subsequently suppressed with

9494-450: 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

9595-471: 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

9696-515: 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

9797-423: The surface of the ground. These stems are called rhizomes . Many fern fronds are initially coiled into a fiddle-head or crozier (see circinate vernation ), although cycad and palm fronds do not have this pattern of new leaf growth. Fronds may bear hairs, scales, glands, and, in some species, bulblets for vegetative reproduction. Fronds may describe several " frondose " structures in non-plant organisms -- such as

9898-526: 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

9999-485: 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

10100-399: 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

10201-412: 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

#527472