92-509: Grün (sometimes transliterated as gruen ) is surname literally meaning " green ". Green Green is the color between cyan and yellow on the visible spectrum . It is evoked by light which has a dominant wavelength of roughly 495–570 nm . In subtractive color systems, used in painting and color printing, it is created by a combination of yellow and cyan; in the RGB color model , used on television and computer screens, it
184-499: A sod -forming perennial grass used in agriculture is Thinopyrum intermedium . Grasses are used as raw material for a multitude of purposes, including construction and in the composition of building materials such as cob , for insulation, in the manufacture of paper and board such as oriented structural straw board . Grass fiber can be used for making paper , biofuel production, nonwoven fabrics, and as replacement for glass fibers used in reinforced plastics. Bamboo scaffolding
276-410: A blue-green color, while the light-adapted eye is most sensitive about 555 nm, a yellow-green; these are the peak locations of the rod and cone (scotopic and photopic, respectively) luminosity functions . The perception of greenness (in opposition to redness forming one of the opponent mechanisms in human color vision ) is evoked by light which triggers the medium-wavelength M cone cells in
368-425: A camouflage in military and other fields. Substances that may impart a greenish hue to one's skin include biliverdin , the green pigment in bile , and ceruloplasmin , a protein that carries copper ions in chelation . The green huntsman spider is green due to the presence of bilin pigments in the spider's hemolymph (circulatory system fluids) and tissue fluids . It hunts insects in green vegetation, where it
460-481: A genuine and widely used term for "green". Related to virere "to grow" and ver "spring", it gave rise to words in several Romance languages , French vert , Italian verde (and English vert , verdure etc.). Likewise the Slavic languages with zelenъ . Ancient Greek also had a term for yellowish, pale green – χλωρός , chloros (cf. the color of chlorine), cognate with χλοερός "verdant" and χλόη " chloe ,
552-538: A green color, including the emerald , which is colored green by its chromium content. During post-classical and early modern Europe, green was the color commonly associated with wealth, merchants, bankers, and the gentry, while red was reserved for the nobility. For this reason, the costume of the Mona Lisa by Leonardo da Vinci and the benches in the British House of Commons are green while those in
644-454: A green dye for clothing, made from the leaves of the birch tree. It was of very poor quality, more brown than green. Ceramics from ancient Mesopotamia show people wearing vivid green costumes, but it is not known how the colors were produced. In Ancient Egypt , green was the symbol of regeneration and rebirth, and of the crops made possible by the annual flooding of the Nile. For painting on
736-499: A meaning that covers both blue and green; blue and green are traditionally considered shades of " 青 ". In more contemporary terms, they are 藍 ( lán , in Mandarin) and 綠 ( lǜ , in Mandarin) respectively. Japanese also has two terms that refer specifically to the color green, 緑 ( midori , which is derived from the classical Japanese descriptive verb midoru "to be in leaf, to flourish" in reference to trees) and グリーン ( guriin , which
828-485: A mix ratio 75:25 of boron and potassium nitrate . Smoke can be turned green by a mixture: solvent yellow 33, solvent green 3, lactose , magnesium carbonate plus sodium carbonate added to potassium chlorate . Green is common in nature, as many plants are green because of a complex chemical known as chlorophyll, which is involved in photosynthesis . Chlorophyll absorbs the long wavelengths of light (red) and short wavelengths of light (blue) much more efficiently than
920-533: A new politics of the left which rejected traditional socialism and communism. (See § In politics section below.) Green can communicate safety to proceed, as in traffic lights . Green and red were standardized as the colors of international railroad signals in the 19th century. The first traffic light, using green and red gas lamps, was erected in 1868 in front of the Houses of Parliament in London. It exploded
1012-584: A photosynthetic pathway, linked to specialized Kranz leaf anatomy , which allows for increased water use efficiency , rendering them better adapted to hot, arid environments. The C3 grasses are referred to as "cool-season" grasses, while the C4 plants are considered "warm-season" grasses. Although the C4 species are all in the PACMAD clade (see diagram below), it seems that various forms of C4 have arisen some twenty or more times, in various subfamilies or genera. In
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#17327914257531104-596: A smaller part of the vegetation in almost every other terrestrial habitat. Grass-dominated biomes are called grasslands. If only large, contiguous areas of grasslands are counted, these biomes cover 31% of the planet's land. Grasslands include pampas , steppes , and prairies . Grasses provide food to many grazing mammals, as well as to many species of butterflies and moths . Many types of animals eat grass as their main source of food, and are called graminivores – these include cattle , sheep , horses , rabbits and many invertebrates , such as grasshoppers and
1196-442: A traditional color wheel, based on subtractive color, the complementary color to green is considered to be red. In additive color devices such as computer displays and televisions, one of the primary light sources is typically a narrow-spectrum yellowish-green of dominant wavelength ~550 nm ; this "green" primary is combined with an orangish-red "red" primary and a purplish-blue "blue" primary to produce any color in between –
1288-910: A variety that include grasses that are related to modern rice and bamboo . Grasses have adapted to conditions in lush rain forests , dry deserts , cold mountains and even intertidal habitats , and are currently the most widespread plant type; grass is a valuable source of food and energy for all sorts of wildlife. A cladogram shows subfamilies and approximate species numbers in brackets: Chloridoideae (1600) Danthonioideae (300) Micrairoideae (200) Arundinoideae (50) Panicoideae (3250) Aristidoideae (350) Oryzoideae (110) Bambusoideae – bamboos (1450) Pooideae (3850) Puelioideae (11) Pharoideae (13) Anomochlooideae (4) Before 2005, fossil findings indicated that grasses evolved around 55 million years ago. Finds of grass-like phytoliths in Cretaceous dinosaur coprolites from
1380-757: Is a commonly used coloring in the United Kingdom but is banned in Australia, Japan, Norway and the United States. Green S (E142) is prohibited in many countries, for it is known to cause hyperactivity , asthma , urticaria , and insomnia . To create green sparks, fireworks use barium salts , such as barium chlorate , barium nitrate crystals, or barium chloride , also used for green fireplace logs. Copper salts typically burn blue, but cupric chloride (also known as "campfire blue") can also produce green flames. Green pyrotechnic flares can use
1472-473: Is a grass used as a culinary herb for its citrus-like flavor and scent. Many species of grass are grown as pasture for foraging or as fodder for prescribed livestock feeds, particularly in the case of cattle , horses , and sheep . Such grasses may be cut and stored for later feeding, especially for the winter, in the form of bales of hay or straw , or in silos as silage . Straw (and sometimes hay) may also be used as bedding for animals. An example of
1564-470: Is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses . It includes the cereal grasses, bamboos , the grasses of natural grassland and species cultivated in lawns and pasture . The latter are commonly referred to collectively as grass . With around 780 genera and around 12,000 species, the Poaceae is the fifth-largest plant family , following
1656-570: Is able to withstand typhoon-force winds that would break steel scaffolding. Larger bamboos and Arundo donax have stout culms that can be used in a manner similar to timber, Arundo is used to make reeds for woodwind instruments , and bamboo is used for innumerable implements. Phragmites australis (common reed) is important for thatching and wall construction of homes in Africa. Grasses are used in water treatment systems, in wetland conservation and land reclamation , and used to lessen
1748-403: Is associated with the east, with sunrise, and with life and growth. In Thailand, the color green is considered auspicious for those born on a Wednesday (light green for those born at night). Green is the color most commonly associated in the United States and Europe with springtime, freshness, and hope. Green is often used to symbolize rebirth and renewal and immortality. In Ancient Egypt ;
1840-513: Is blood red and pale yellow, with a green billiard table in the center, and four lamps of lemon yellow, with rays of orange and green. Everywhere it is a battle and antithesis of the most different reds and greens." In the 1980s, green became a political symbol, the color of the Green Party in Germany and in many other European countries. It symbolized the environmental movement , and also
1932-485: Is cognate with the Ancient Greek γλαυκός "bluish green", contrasting with χλωρός "yellowish green" discussed above. In modern Japanese, the term for green is 緑 , while the old term for "blue/green", blue ( 青 , Ao ) now means "blue". But in certain contexts, green is still conventionally referred to as 青, as in blue traffic light ( 青信号 , ao shingō ) and blue leaves ( 青葉 , aoba ) , reflecting
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#17327914257532024-516: Is derived from the English word "green"). However, in Japan, although the traffic lights have the same colors as other countries have, the green light is described using the same word as for blue, aoi , because green is considered a shade of aoi; similarly, green variants of certain fruits and vegetables such as green apples, green shiso (as opposed to red apples and red shiso) will be described with
2116-606: Is linked to crop improvement, since meiotic recombination is an important component of plant breeding . Unlike in animals, the specification of both male and female plant germlines occurs late in development during flowering. The transition from the sporophyte phase to the gametophyte state is initiated by meiotic entry. Grasses are, in human terms, perhaps the most economically important plant family. Their economic importance stems from several areas, including food production, industry, and lawns . They have been grown as food for domesticated animals for up to 6,000 years and
2208-425: Is missing or faulty, which can cause color blindness , including the common inability to distinguish red and yellow from green, known as deuteranopia or red-green color blindness. Green is restful to the eye. Studies show that a green environment can reduce fatigue. In the subtractive color system, used in painting and color printing, green is created by a combination of yellow and blue, or yellow and cyan ; in
2300-430: Is one of the additive primary colors , along with red and blue , which are mixed in different combinations to create all other colors. By far the largest contributor to green in nature is chlorophyll , the chemical by which plants photosynthesize and convert sunlight into chemical energy. Many creatures have adapted to their green environments by taking on a green hue themselves as camouflage . Several minerals have
2392-482: Is rarely found in Greek art. The Romans had a greater appreciation for the color green; it was the color of Venus , the goddess of gardens, vegetables and vineyards. The Romans made a fine green earth pigment that was widely used in the wall paintings of Pompeii , Herculaneum , Lyon , Vaison-la-Romaine , and other Roman cities. They also used the pigment verdigris, made by soaking copper plates in fermenting wine. By
2484-518: Is the color most commonly associated in Europe and the United States with nature, vivacity and life. It is the color of many environmental organizations, such as Greenpeace , and of the Green Parties in Europe. Many cities have designated a garden or park as a green space, and use green trash bins and containers. A green cross is commonly used to designate pharmacies in Europe. In China, green
2576-447: Is then passed through another crystal containing potassium, titanium and phosphorus (KTP), whose non-linear properties generate light at a frequency that is twice that of the incident beam (563.5 THz); in this case corresponding to the wavelength of 532 nm ("green"). Other green wavelengths are also available using DPSS technology ranging from 501 nm to 543 nm. Green wavelengths are also available from gas lasers , including
2668-583: Is well camouflaged. There is no green pigment in green eyes; like the color of blue eyes, it is an optical illusion; its appearance is caused by the combination of an amber or light brown pigmentation of the stroma , given by a low or moderate concentration of melanin , with the blue tone imparted by the Rayleigh scattering of the reflected light. Nobody is brought into the world with green eyes. An infant has one of two eye hues: dark or blue. Following birth, cells called melanocytes start to discharge melanin,
2760-454: The Aristida genus for example, one species ( A. longifolia ) is C3 but the approximately 300 other species are C4. As another example, the whole tribe of Andropogoneae , which includes maize , sorghum , sugar cane , " Job's tears ", and bluestem grasses , is C4. Around 46 percent of grass species are C4 plants. The name Poaceae was given by John Hendley Barnhart in 1895, based on
2852-720: The Albian stage of the Early Cretaceous approximately 113–100 million years ago, which were found to belong to primitive lineages within Poaceae, similar in position to the Anomochlooideae. These are currently the oldest known grass fossils. The relationships among the three subfamilies Bambusoideae, Oryzoideae and Pooideae in the BOP clade have been resolved: Bambusoideae and Pooideae are more closely related to each other than to Oryzoideae. This separation occurred within
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2944-508: The Americas ). Sugarcane is the major source of sugar production. Additional food uses of sugarcane include sprouted grain , shoots , and rhizomes , and in drink they include sugarcane juice and plant milk , as well as rum , beer , whisky , and vodka . Bamboo shoots are used in numerous Asian dishes and broths, and are available in supermarkets in various sliced forms, in both fresh, fermented and canned versions. Lemongrass
3036-556: The Asteraceae , Orchidaceae , Fabaceae and Rubiaceae . The Poaceae are the most economically important plant family, providing staple foods from domesticated cereal crops such as maize , wheat , rice , oats , barley , and millet for people and as feed for meat-producing animals . They provide, through direct human consumption, just over one-half (51%) of all dietary energy; rice provides 20%, wheat supplies 20%, maize (corn) 5.5%, and other grains 6%. Some members of
3128-458: The Cenozoic contributed to the spread of grasses. Without large grazers, fire-cleared areas are quickly colonized by grasses, and with enough rain, tree seedlings. Trees eventually outcompete most grasses. Trampling grazers kill seedling trees but not grasses. Sexual reproduction and meiosis have been studied in rice , maize , wheat and barley . Meiosis research in these crop species
3220-593: The European Union and the United States , green is also sometimes associated with toxicity and poor health, but in China and most of Asia, its associations are very positive, as the symbol of fertility and happiness. Because of its association with nature, it is the color of the environmental movement . Political groups advocating environmental protection and social justice describe themselves as part of
3312-776: The Food Safety and Standards Act of 2006 with changes to symbolism since but still maintaining the color green. In 2021, India introduced a green V to exclusively label vegan options. In the west, the V-Label , a green V designed by the European Vegetarian Union , has been used by food distributors to label vegan and vegetarian options. grass Gramineae Juss. Poaceae ( / p oʊ ˈ eɪ s i . iː , - s i aɪ / poh- AY -see-e(y)e ), also called Gramineae ( / ɡ r ə ˈ m ɪ n i . iː , - n i aɪ / grə- MIN -ee-e(y)e ),
3404-690: The German word grün , has the same root as the words grass and grow . It is from a Common Germanic *gronja - , which is also reflected in Old Norse grænn , Old High German gruoni (but unattested in East Germanic ), ultimately from a PIE root * ghre- "to grow", and root-cognate with grass and to grow . The first recorded use of the word as a color term in Old English dates to ca. AD 700. Latin with viridis also has
3496-548: The Green movement , some naming themselves Green parties . This has led to similar campaigns in advertising, as companies have sold green, or environmentally friendly , products. Green is also the traditional color of safety and permission; a green light means go ahead, a green card permits permanent residence in the United States. The word green comes from the Middle English and Old English word grene , which, like
3588-606: The House of Lords are red. It also has a long historical tradition as the color of Ireland and of Gaelic culture . It is the historic color of Islam , representing the lush vegetation of Paradise . It was the color of the banner of Muhammad , and is found in the flags of nearly all Islamic countries. In surveys made in American , European, and Islamic countries , green is the color most commonly associated with nature , life , health , youth , spring , hope , and envy . In
3680-457: The RGB color model , used on television and computer screens, it is one of the additive primary colors , along with red and blue, which are mixed in different combinations to create all other colors. On the HSV color wheel , also known as the RGB color wheel , the complement of green is magenta ; that is, a color corresponding to an equal mixture of red and blue light (one of the purples ). On
3772-632: The helium–neon laser (543 nm), the Argon- ion laser (514 nm) and the Krypton-ion laser (521 nm and 531 nm), as well as liquid dye lasers . Green lasers have a wide variety of applications, including pointing, illumination, surgery, laser light shows , spectroscopy , interferometry , fluorescence , holography , machine vision , non-lethal weapons , and bird control . As of mid-2011, direct green laser diodes at 510 nm and 500 nm have become generally available, although
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3864-422: The ligule lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath. Flowers of Poaceae are characteristically arranged in spikelets , each having one or more florets. The spikelets are further grouped into panicles or spikes . The part of the spikelet that bears the florets is called the rachilla. A spikelet consists of two (or sometimes fewer) bracts at
3956-448: The 16th century was a good green dye produced, by first dyeing the cloth blue with woad, and then yellow with Reseda luteola , also known as yellow-weed. The pigments available to painters were more varied; monks in monasteries used verdigris, made by soaking copper in fermenting wine, to color medieval manuscripts. They also used finely-ground malachite, which made a luminous green. They used green earth colors for backgrounds. During
4048-453: The English adjective orange being in origin not a color term but the name of a fruit). Thus, the Thai word เขียว kheīyw , besides meaning "green", also means "rank" and "smelly" and holds other unpleasant associations. The Celtic languages had a term for "blue/green/grey", Proto-Celtic *glasto- , which gave rise to Old Irish glas "green, grey" and to Welsh glas "blue". This word
4140-562: The Poaceae are used as building materials ( bamboo , thatch , and straw ); others can provide a source of biofuel , primarily via the conversion of maize to ethanol . Grasses have stems that are hollow except at the nodes and narrow alternate leaves borne in two ranks. The lower part of each leaf encloses the stem, forming a leaf-sheath. The leaf grows from the base of the blade, an adaptation allowing it to cope with frequent grazing. Grasslands such as savannah and prairie where grasses are dominant are estimated to constitute 40.5% of
4232-499: The RGB color model. A unique green (green appearing neither yellowish nor bluish) is produced on such a device by mixing light from the green primary with some light from the blue primary. Lasers emitting in the green part of the spectrum are widely available to the general public in a wide range of output powers. Green laser pointers outputting at 532 nm (563.5 THz ) are relatively inexpensive compared to other wavelengths of
4324-685: The Slavic zelenъ is cognate with Sanskrit harithah "yellow, ochre, golden". The Turkic languages also have jašɨl "green" or "yellowish green", compared to a Mongolian word for "meadow". In some languages, including old Chinese , Thai , old Japanese , and Vietnamese , the same word can mean either blue or green. The Chinese character 青 (pronounced qīng in Mandarin , ao in Japanese, and thanh in Sino-Vietnamese ) has
4416-415: The absence of blue-green distinction in old Japanese (more accurately, the traditional Japanese color terminology grouped some shades of green with blue, and others with yellow tones). In optics, the perception of green is evoked by light having a spectrum dominated by energy with a wavelength of roughly 495–570 nm . The sensitivity of the dark-adapted human eye is greatest at about 507 nm,
4508-403: The analogy to immature and unripe fruit. Examples include green cheese , a term for a fresh, unaged cheese, and greenhorn , an inexperienced person. The color green has been increasingly used by food companies, governments, and practitioners themselves to identify veganism and vegetarianism. The government of India requires food that is vegetarian to be marked with a green circle as part of
4600-442: The base, called glumes , followed by one or more florets. A floret consists of the flower surrounded by two bracts, one external—the lemma —and one internal—the palea . The flowers are usually hermaphroditic — maize being an important exception—and mainly anemophilous or wind-pollinated, although insects occasionally play a role. The perianth is reduced to two scales, called lodicules , that expand and contract to spread
4692-417: The blue-green color is likely to be derived from small quantities of lead and water in the feldspar . Copper is the source of the green color in malachite pigments, chemically known as basic copper(II) carbonate . Verdigris is made by placing a plate or blade of copper, brass or bronze, slightly warmed, into a vat of fermenting wine, leaving it there for several weeks, and then scraping off and drying
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#17327914257534784-520: The bride in the Arnolfini portrait by Jan van Eyck . There were no good vegetal green dyes which resisted washing and sunlight for those who wanted or were required to wear green. Green dyes were made out of the fern , plantain , buckthorn berries, the juice of nettles and of leeks , the digitalis plant, the broom plant, the leaves of the fraxinus , or ash tree, and the bark of the alder tree, but they rapidly faded or changed color. Only in
4876-450: The caterpillars of many brown butterflies . Grasses are also eaten by omnivorous or even occasionally by primarily carnivorous animals. Grasses dominate certain biomes , especially temperate grasslands , because many species are adapted to grazing and fire. Grasses are unusual in that the meristem is near the bottom of the plant; hence, grasses can quickly recover from cropping at the top. The evolution of large grazing animals in
4968-407: The color of the sea and the color of trees. The philosopher Democritus described two different greens: chloron , or pale green, and prasinon , or leek green. Aristotle considered that green was located midway between black, symbolizing the earth, and white, symbolizing water. However, green was not counted among the four classic colors of Greek painting – red, yellow, black and white – and
5060-476: The comparative study of color terms in the world's languages, green is only found as a separate category in languages with the fully developed range of six colors (white, black, red, green, yellow, and blue), or more rarely in systems with five colors (white, red, yellow, green, and black/blue). These languages have introduced supplementary vocabulary to denote "green", but these terms are recognizable as recent adoptions that are not in origin color terms (much like
5152-484: The early Renaissance, painters such as Duccio di Buoninsegna learned to paint faces first with a green undercoat, then with pink, which gave the faces a more realistic hue. Over the centuries the pink has faded, making some of the faces look green. The 18th and 19th centuries brought the discovery and production of synthetic green pigments and dyes, which rapidly replaced the earlier mineral and vegetable pigments and dyes. These new dyes were more stable and brilliant than
5244-693: The earthy colored shade, in the child's irises. This begins happening since melanocytes respond to light in time. Green eyes are most common in Northern and Central Europe . They can also be found in Southern Europe , West Asia , Central Asia , and South Asia . In Iceland , 89% of women and 87% of men have either blue or green eye color. A study of Icelandic and Dutch adults found green eyes to be much more prevalent in women than in men. Neolithic cave paintings do not have traces of green pigments, but neolithic peoples in northern Europe did make
5336-835: The erosional impact of urban storm water runoff. Pollen morphology, particularly in the Poaceae family, is key to figuring out their evolutionary relationships and how environments have changed over time . Grass pollen grains, however, often look the same, making it hard to use them for detailed climate or environmental reconstructions. Grass pollen has a single pore and can vary a lot in size, from about 20 to over 100 micrometers, and this size difference has been looked into for clues about past habitats, to tell apart domesticated grasses from wild ones, and to indicate various biological features like how they perform photosynthesis , their breeding systems, and genetic complexity. Yet, there's ongoing debate about how effective pollen size
5428-427: The extraction of light were selected to exploit those portions of the spectrum not used by the halobacteria. Animals typically use the color green as camouflage , blending in with the chlorophyll green of the surrounding environment. Most fish, reptiles, amphibians, and birds appear green because of a reflection of blue light coming through an over-layer of yellow pigment. Perception of color can also be affected by
5520-423: The eye more than the long-wavelength L cones. Light which triggers this greenness response more than the yellowness or blueness of the other color opponent mechanism is called green. A green light source typically has a spectral power distribution dominated by energy with a wavelength of roughly 487–570 nm. Human eyes have color receptors known as cone cells, of which there are three types. In some cases, one
5612-564: The following year, injuring the policeman who operated it. In 1912, the first modern electric traffic lights were put up in Salt Lake City , Utah . Red was chosen largely because of its high visibility, and its association with danger, while green was chosen largely because it could not be mistaken for red. Today green lights universally signal that a system is turned on and working as it should. In many video games, green signifies both health and completed objectives, opposite red. Green
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#17327914257535704-469: The full list of Poaceae genera . The grass family is one of the most widely distributed and abundant groups of plants on Earth . Grasses are found on every continent, including Antarctica . The Antarctic hair grass, Deschampsia antarctica is one of only two plant species native to the western Antarctic Peninsula . Grasses are the dominant vegetation in many habitats, including grassland , salt-marsh , reedswamp and steppes . They also occur as
5796-451: The god Osiris , king of the underworld, was depicted as green-skinned. Green as the color of hope is connected with the color of springtime; hope represents the faith that things will improve after a period of difficulty, like the renewal of flowers and plants after the winter season. Green the color most commonly associated in Europe and the United States with youth. It also often is used to describe anyone young, inexperienced, probably by
5888-478: The grains of grasses such as wheat , rice, maize (corn) and barley have been the most important human food crops . Grasses are also used in the manufacture of thatch , paper , fuel , clothing , insulation , timber for fencing , furniture , scaffolding and construction materials, floor matting , sports turf and baskets . Of all crops grown, 70% are grasses. Agricultural grasses grown for their edible seeds are called cereals or grains (although
5980-399: The green of new growth". Thus, the languages mentioned above (Germanic, Romance, Slavic, Greek) have old terms for "green" which are derived from words for fresh, sprouting vegetation. However, comparative linguistics makes clear that these terms were coined independently, over the past few millennia, and there is no identifiable single Proto-Indo-European or word for "green". For example,
6072-579: The green powder that forms on the metal. The process of making verdigris was described in ancient times by Pliny . It was used by the Romans in the murals of Pompeii, and in Celtic medieval manuscripts as early as the 5th century AD. It produced a blue-green which no other pigment could imitate, but it had drawbacks: it was unstable, it could not resist dampness, it did not mix well with other colors, it could ruin other colors with which it came into contact, and it
6164-463: The land area of the Earth , excluding Greenland and Antarctica . Grasses are also an important part of the vegetation in many other habitats, including wetlands , forests and tundra . Though they are commonly called "grasses", groups such as the seagrasses , rushes and sedges fall outside this family. The rushes and sedges are related to the Poaceae, being members of the order Poales , but
6256-453: The latest Cretaceous ( Maastrichtian ) aged Lameta Formation of India have pushed this date back to 66 million years ago. In 2011, fossils from the same deposit were found to belong to the modern rice tribe Oryzeae , suggesting substantial diversification of major lineages by this time. In 2018, a study described grass microfossils extracted from the teeth of the hadrosauroid dinosaur Equijubus normani from northern China, dating to
6348-624: The latter term, when used agriculturally, refers to both cereals and similar seeds of other plant species, such as buckwheat and legumes ). Three cereals—rice, wheat, and maize (corn)—provide more than half of all calories consumed by humans. Cereals constitute the major source of carbohydrates for humans and perhaps the major source of protein; these include rice (in southern and eastern Asia ), maize (in Central and South America ), and wheat and barley (in Europe , northern Asia and
6440-463: The leaves are attached. Grass leaves are nearly always alternate and distichous (in one plane), and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem and a blade with entire (i.e., smooth) margins. The leaf blades of many grasses are hardened with silica phytoliths , which discourage grazing animals; some, such as sword grass , are sharp enough to cut human skin. A membranous appendage or fringe of hairs called
6532-469: The lemma and palea; these are generally interpreted to be modified sepals. The fruit of grasses is a caryopsis , in which the seed coat is fused to the fruit wall. A tiller is a leafy shoot other than the first shoot produced from the seed. Grass blades grow at the base of the blade and not from elongated stem tips. This low growth point evolved in response to grazing animals and allows grasses to be grazed or mown regularly without severe damage to
6624-684: The lush green of rural landscapes and forests. Green was contrasted to the smoky grays and blacks of the Industrial Revolution. The second half of the 19th century saw the use of green in art to create specific emotions, not just to imitate nature. One of the first to make color the central element of his picture was the American artist James McNeill Whistler , who created a series of paintings called "symphonies" or "noctures" of color, including Symphony in gray and green; The Ocean between 1866 and 1872. The late 19th century also brought
6716-441: The more notable green minerals, however is the emerald , which is colored green by trace amounts of chromium and sometimes vanadium . Chromium(III) oxide (Cr 2 O 3 ), is called chrome green , also called viridian or institutional green when used as a pigment. For many years, the source of amazonite 's color was a mystery. Widely thought to have been due to copper because copper compounds often have blue and green colors,
6808-400: The plant. Three general classifications of growth habit present in grasses: bunch-type (also called caespitose), stoloniferous , and rhizomatous . The success of the grasses lies in part in their morphology and growth processes and in part in their physiological diversity. There are both C3 and C4 grasses, referring to the photosynthetic pathway for carbon fixation. The C4 grasses have
6900-547: The price remains relatively prohibitive for widespread public use. The efficiency of these lasers (peak 3%) compared to that of DPSS green lasers (peak 35%) may also be limiting adoption of the diodes to niche uses. Many minerals provide pigments which have been used in green paints and dyes over the centuries. Pigments, in this case, are minerals which reflect the color green, rather that emitting it through luminescent or phosphorescent qualities. The large number of green pigments makes it impossible to mention them all. Among
6992-629: The relatively short time span of about 4 million years. According to Lester Charles King , the spread of grasses in the Late Cenozoic would have changed patterns of hillslope evolution favouring slopes that are convex upslope and concave downslope and lacking a free face were common. King argued that this was the result of more slowly acting surface wash caused by carpets of grass which in turn would have resulted in relatively more soil creep . There are about 12,000 grass species in about 771 genera that are classified into 12 subfamilies. See
7084-475: The roots of the woad plant. For the ancient Egyptians, green had very positive associations. The hieroglyph for green represented a growing papyrus sprout, showing the close connection between green, vegetation, vigor and growth. In wall paintings, the ruler of the underworld, Osiris , was typically portrayed with a green face, because green was the symbol of good health and rebirth. Palettes of green facial makeup, made with malachite, were found in tombs. It
7176-459: The same power, and are very popular due to their good beam quality and very high apparent brightness. The most common green lasers use diode pumped solid state ( DPSS ) technology to create the green light. An infrared laser diode at 808 nm is used to pump a crystal of neodymium- doped yttrium vanadium oxide (Nd:YVO4) or neodymium-doped yttrium aluminium garnet (Nd:YAG) and induces it to emit 281.76 THz (1064 nm). This deeper infrared light
7268-412: The seagrasses are members of the order Alismatales . However, all of them belong to the monocot group of plants. Grasses may be annual or perennial herbs , generally with the following characteristics (the image gallery can be used for reference): The stems of grasses, called culms , are usually cylindrical (more rarely flattened, but not 3-angled) and are hollow, plugged at the nodes , where
7360-558: The second century AD, the Romans were using green in paintings, mosaics and glass, and there were ten different words in Latin for varieties of green. In the Middle Ages and Renaissance, the color of clothing showed a person's social rank and profession. Red could only be worn by the nobility, brown and gray by peasants, and green by merchants, bankers and the gentry and their families. The Mona Lisa wears green in her portrait, as does
7452-572: The surrounding environment. For example, broadleaf forests typically have a yellow-green light about them as the trees filter the light. Turacoverdin is one chemical which can cause a green hue in birds, especially. Invertebrates such as insects or mollusks often display green colors because of porphyrin pigments, sometimes caused by diet. This can causes their feces to look green as well. Other chemicals which generally contribute to greenness among organisms are flavins (lychochromes) and hemanovadin. Humans have imitated this by wearing green clothing as
7544-420: The systematic study of color theory, and particularly the study of how complementary colors such as red and green reinforced each other when they were placed next to each other. These studies were avidly followed by artists such as Vincent van Gogh . Describing his painting, The Night Cafe , to his brother Theo in 1888, Van Gogh wrote: "I sought to express with red and green the terrible human passions. The hall
7636-403: The tribe Poeae described in 1814 by Robert Brown , and the type genus Poa described in 1753 by Carl Linnaeus . The term is derived from the Ancient Greek πόα (póa, "fodder") . Grasses include some of the most versatile plant life-forms . They became widespread toward the end of the Cretaceous period, and fossilized dinosaur dung ( coprolites ) have been found containing phytoliths of
7728-400: The vegetable dyes, but some contained high levels of arsenic , and were eventually banned. In the 18th and 19th centuries, green was associated with the romantic movement in literature and art. The German poet and philosopher Goethe declared that green was the most restful color, suitable for decorating bedrooms. Painters such as John Constable and Jean-Baptiste-Camille Corot depicted
7820-426: The walls of tombs or on papyrus, Egyptian artists used finely ground malachite , mined in the west Sinai and the eastern desert; a paintbox with malachite pigment was found inside the tomb of King Tutankhamun . They also used less expensive green earth pigment, or mixed yellow ochre and blue azurite . To dye fabrics green, they first colored them yellow with dye made from saffron and then soaked them in blue dye from
7912-433: The wavelengths that appear green to the human eye, so light reflected by plants is enriched in green. Chlorophyll absorbs green light poorly because it first arose in organisms living in oceans where purple halobacteria were already exploiting photosynthesis. Their purple color arose because they extracted energy in the green portion of the spectrum using bacteriorhodopsin . The new organisms that then later came to dominate
8004-487: The word aoi . Vietnamese uses a single word for both blue and green, xanh , with variants such as xanh da trời (azure, lit. "sky blue"), lam (blue), and lục (green; also xanh lá cây , lit. "leaf green"). "Green" in modern European languages corresponds to about 520–570 nm, but many historical and non-European languages make other choices, e.g. using a term for the range of ca. 450–530 nm ("blue/green") and another for ca. 530–590 nm ("green/yellow"). In
8096-430: Was toxic . Leonardo da Vinci , in his treatise on painting, warned artists not to use it. It was widely used in miniature paintings in Europe and Persia in the 16th and 17th centuries. Its use largely ended in the late 19th century, when it was replaced by the safer and more stable chrome green . Viridian, as described above, was patented in 1859. It became popular with painters, since, unlike other synthetic greens, it
8188-629: Was a new synthetic green created by a chemist named Pannetier in Paris in about 1835. Emerald green was a synthetic deep green made in the 19th century by hydrating chrome oxide. It was also known as Guignet green. There is no natural source for green food colorings which has been approved by the US Food and Drug Administration . Chlorophyll, the E numbers E140 and E141, is the most common green chemical found in nature, and only allowed in certain medicines and cosmetic materials. Quinoline Yellow (E104)
8280-461: Was crushed, washed to remove impurities, then powdered. It was sometimes called Green of Verona. Mixtures of oxidized cobalt and zinc were also used to create green paints as early as the 18th century. Cobalt green , sometimes known as Rinman's green or zinc green, is a translucent green pigment made by heating a mixture of cobalt (II) oxide and zinc oxide. Sven Rinman , a Swedish chemist, discovered this compound in 1780. Green chrome oxide
8372-700: Was stable and not toxic. Vincent van Gogh used it, along with Prussian blue , to create a dark blue sky with a greenish tint in his painting Café Terrace at Night . Green earth is a natural pigment used since the time of the Roman Empire . It is composed of clay colored by iron oxide , magnesium , aluminum silicate , or potassium . Large deposits were found in the South of France near Nice , and in Italy around Verona , on Cyprus , and in Bohemia . The clay
8464-429: Was worn by both the living and the dead, particularly around the eyes, to protect them from evil. Tombs also often contained small green amulets in the shape of scarab beetles made of malachite, which would protect and give vigor to the deceased. It also symbolized the sea, which was called the "Very Green". In Ancient Greece, green and blue were sometimes considered the same color, and the same word sometimes described
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