Polystichum Polystichum is a genus of about 180 species of ferns with a cosmopolitan distribution. The highest diversity is in eastern Asia, with about 120 species in China alone; Africa, North America, and Europe have much lower diversity. Many ferns of this genus have stout, slowly-creeping rootstocks that form a crown, with a vase-like ring of evergreen fronds 30-200 cm long.
	Polystichum acrostichoides Polystichum acrostichoides is a fern References
	Polystichum aculeatum Polystichum aculeatum is an evergreen fern native to Europe. It is most abundant in upland regions of the British Isles and western France, where it benefits from the combination of mild winters and moist summers, but also occurs more locally across most of Europe except northern Scandinavia, northern Russia; in the Mediterranean region it is confined to high altitudes.
	Polystichum setiferum Polystichum aculeatum is an evergreen or semi-evergreen fern native to southern and western Europe. It is most abundant in Ireland, southwestern Great Britain, western France and northwest Iberia, where it benefits from the combination of mild winters and moist summers, but also occurs more locally north to northern Scotland and east to the Crimea and Turkey; in the Mediterranean region it usually grows at high altitudes.
	Polystyrene Polystyrene is a polymer made from the monomer styrene, a liquid hydrocarbon that is commercially manufactured from petroleum. At room temperature, polystyrene is normally a solid thermoplastic, but can be melted at higher temperature for Molding or extrusion, then resolidified.
	Polytetrafluoroethylene Polytetrafluoroethylene is a fluoropolymer discovered by Roy J. Plunkett of DuPont in 1938. It was introduced as a commercial product in 1946 and is generally known to the public by DuPont's brand name Teflon. PTFE has the lowest coefficient of friction of any known solid material.
	Polytonality The musical use of more than one key simultaneity is polytonality. Bitonality is the use of only two different keys at the same time. A well-known, though not uncontroversial, example is the fanfare at the beginning of the second tableau of Igor Stravinsky's ballet, Petrushka.
	Polyunsaturated fat In nutrition, polyunsaturated fats are a fatty acid in which more than one double bond exists within the representative molecule. That is, the molecule has two or more points on its structure capable of supporting hydrogen atoms not currently part of the structure. Polysaturated fatty acids can assume a cis or trans
	Polyurethane A polyurethane is any polymer consisting of a chain of organic chemistry units joined by carbamate links. It is widely used in flexible and rigid foams, durable elastomers and high performance adhesives and sealants, Synthetic fiber, seal s, gaskets, condoms, carpet underlay, and hard plastic parts.
	Polyvinyl acetate Polyvinyl acetate or PVA is a rubbery synthetic polymer. It can also be referred to as PVAc. It is prepared by polymerization of vinyl acetate, also referred to as VAM. Partial or complete hydrolysis of the polymer is used to prepare polyvinyl alcohol. Hydroylized alcohol product is typically in the 87% to 99% range.
	Polyvinyl chloride Polyvinyl chloride, commonly abbreviated PVC, is a widely-used plastic. In terms of revenue generated, it is one of the most valuable products of the chemical industry. Globally, over 50% of PVC manufactured is used in construction. As a building material, PVC is cheap and easy to assemble.
	Pomacanthus Pomacanthus is a genus of marine angelfish that is usually found around reefs and coral. Some of the notable places one can see these vari-coloured fish includes the Maldives, Sri Lanka, and Sipidan off the southern coast of Sabah, Malaysia.
	Pomacentridae Pomacentridae is a family of perciform fish, comprising the damselfishes and clownfishes. They are exclusively ocean, and noted for their hardy constitutions and territoriality. Many are brightly coloured, so they are popular in aquarium. Around 360 species are classified in this family, in approximately 28 genus.
	Pomacentrus Pomacentrus is a genus of fish in the family Pomacentridae.
	Pome In botany, a pome is a type of fruit produced by flowering plants in the Subfamily Maloideae of the Family Rosaceae. A pome is an accessory fruit composed of five or more carpels in which the exocarp forms an inconspicuous layer, the mesocarp is usually fleshy, and the endocarp forms a leathery case around the seed.
	Pomegranate The Pomegranate is a fruit-bearing deciduous shrub or small tree growing to 5–8 m tall. The pomegranate is believed to have originated in eastern Iran and eastward, but its true native range is not accurately known because of millennia of extensive cultivation.
	Pomelo The pomelo, Citrus maxima, also Citrus grandis, is a citrus fruit, usually a pale green to yellow when ripe, larger than a grapefruit, with sweet flesh and thick spongy rind.
	Pomfret Pomfret are perciform fishes belonging to the family Bramidae. They are found in the Atlantic, Indian Ocean, and Pacific Oceans, and the largest species, the Atlantic pomfret, Brama brama, grows up to one metre long. Several species are important food fish in some parts of the world, especially Brama brama in south Asia.
	Pommel horse The pommel horse is an artistic gymnastics apparatus. It is only used by male gymnasts. Originally made of a metal frame with a wooden body and a leather cover, today the frame may contain plastic or composite materials, the body is made of plastic and may be covered with synthetic materials.
	Pompadour Pompadour is a style of haircut which takes its name from Madame de Pompadour. The pompadour was a fashion trend in the 1950s among male rockabilly artists and actors in the 1950s like Elvis Presley, Marlon Brando and James Dean; in the late twentieth century, rockabilly revival musician Brian Setzer and Pretenders bassist Pete Farndon were known for wearing this style.
	Pompano Pompanos are marine fishes in the Trachinotus genus of the Carangidae family. Pompano may also refer to various members of the Carangidae family and Perciforme order. Their appearance is deep bodied and mackerel-like, typically silver colored and toothless with a forked tail and narrow base.
	Pompeii Pompeii is a ruined Ancient Rome city near modern Naples in the Italy region of Campania, in the territory of the commune of Pompei. It was destroyed during a catastrophic volcano of the volcano Mount Vesuvius in AD 79. The volcano buried the city under many feet of ash and it was lost for 1,600 years before its accidental rediscovery.
	Pompey Pompey, Pompey the Great or Pompey the Triumvir , was a distinguished military and political leader of the late Roman republic. Hailing from an Italian provincial background, he went on to establish a place for himself in the ranks of Roman nobility, and was given the cognomen of List of Roman cognomina#M the Great by Sulla.
	Ponca The Ponca are a Native Americans in the United States tribe which currently has about 1300 members and which has its tribal headquarters in Niobrara, Nebraska. At the time they first appeared in written history, the Ponca lived around the mouth of the Niobrara River, Nebraska.
	Poncho A poncho is a simple garment designed to keep the body warm, or if made from an impermeable material, to keep dry during rain. It is essentially a single large sheet of fabric with an opening for the head and sometimes for the arms. Some ponchos, especially those made to ward off rain, also have hoods attached.
	Pond A pond is a body of water smaller than a lake. However the difference between a pond and a lake is subjective.
	Ponderosa Pine Ponderosa Pine is a widespread and very variable pine native to western North America. See the table below for the botanical characters of the different types. In most texts separated into two varieties, modern forestry research has shown that there are four different taxa of Ponderosa Pine, with differing botanical characters and adapted to very different climatic conditions.
	Pong PONG is a computer and video games by Atari, based on the sport of table tennis. "Pong" is the title of an entire genre of PONG derived arcade units, consoles and games based on the "ball" and "paddle" characteristic of game play. Though PONG is commonly thought to be the world's first video arcade game, Computer Space actually preceded it.
	Pontederia Pontederia is a genus of aquatic plants, commonly called the pickerel weeds. Pontederia is endemic to the Americas, distributed from Canada to Argentina, where it is found in patrially submerged in shallow water or on mud. The genus was named by Carolus Linnaeus in honour of the Italian botanist Giulio Pontedera.
	Pontederiaceae Pontederiaceae is the botanical name of a family of flowering plants. Such a family has been recognized by relatively few taxonomists. The APG II system, of 2003, does recognize such a family and places it in the order Commelinales, in the clade commelinids, in the monocots.
	Pontiac Pontiac is a marque of automobile produced by General Motors Corporation and sold in the United States and Canada from 1926 to the present. In the GM brand lineup, Pontiac is a mid-level brand featuring a more sporting, performance-driving experience for a reasonable price, and a youthful feel to its advertising.
	Pontius Pilate Pontius Pilate was the Roman governor of the Roman Empire Iudaea Province from 26 until 36. In modern times he is best known as the man who, according to the Biblical canon Christianity Gospels, presided over the Sanhedrin Trial of Jesus and ordered his crucifixion, instigating the Passion.
	Pontoon A pontoon is a flat-bottomed boat or the floats used to support a structure on water. It may be simply constructed from closed cylinders such as pipes or barrels or fabricated as boxes from metal or concrete. These may be used to support a simple platform, creating a raft.
	Pontoon bridge Pontoon bridges are floating bridges supported by barge-or-boat-like pontoons to support the bridge deck and its dynamic loads. While pontoon bridges are usually temporary structures, some are used for long periods of time. Permanent floating bridges are useful for sheltered water-crossings where it is not considered economically feasible to suspend a bridge from anchored piers.
	Pontus Pontus is the name which was applied, in ancient times, to extensive tracts of country in the northeast of Anatolia bordering on the Euxine, which was often called simply Pontos, by the Ancient Greece, after the colonisation of the Anatolian and other Black Sea shores by the Ionian Greeks.
	Pony A pony is a certain kind of small horse. Ponies are 14.2 Hand at the withers or smaller, while a horse is anything taller than 14.2 hh at the withers. The term "pony" can be used generally for any small horse or colt, regardless of its actual measurements. It is interesting to note, however, that some equine breeds are not considered ponies, even if they are under 14.2 hh, because of their fiery temperament.
	Pony Express The Pony Express was a fast mail service crossing the North American continent from the Missouri River to the Pacific coast, operating from April 1860 to November 1861. Messages were carried on horseback relay across the prairies, plains, deserts, and mountains of the western United States.
	Ponytail | |} A ponytail is a hairstyle in which most or all of the hair on the head is pulled away from the face, gathered and secured at the back of the head with a hair tie, clip or similar device, and allowed to hang freely from that point. It gets its name from its resemblance to the undocked tail of a horse or pony.
	Poodle akcgroup = Standard and Miniature: Nonsporting; Toy: Toy | akcstd = ankcgroup = Group 7 | ankcstd = Standard], , ] or Germany | fcigroup = 9 | fcinum = 172 | fcisection = 2 | fcistd = image = Poodle.jpg | image_caption = White Standard Poodle. | kcukgroup = Utility | kcukstd = Standard], , , , , ] of dog; specifically, it is a gun dog noted for its ability in the water and bird hunting skills.
	Poop deck In naval architecture, a poop deck is a deck that constitutes the roof of a poop cabin built in the aft part of the superstructure of a ship. The name originates from the Latin puppis, or the elevated stern deck. In sailing ships, with the steerage at the stern, an elevated position was ideal for both navigation and observation of the crew.
	Poorhouse References *Illustrated History of Long Term Care. External link Category:Public housing
	Pop art Pop art was a visual History of art that emerged in the late 1950s in England and the United States. Characterized by themes and techniques drawn from mass culture, such as advertising and comic books, pop art is widely interpreted as either a reaction to the then-dominant ideas of abstract expressionism or an expansion upon them.
	Pop music Pop music is a music genre of popular music distinguished from Classical music or art music and from folk music . The term indicates specific stylistic traits, but the genre also includes elements of rock music, Hip hop music, dance music,and Country music, making it a flexible category.
	Popcorn Popcorn or popping corn is a type of maize which puffs up when it is heated in oil or by dry heat. Special varieties of corn are grown to give improved popping yield. Some wild types will pop, but the cultivated strain is Zea mays subsp. mays, which is a special kind of flint corn.
	Pope The Pope is the Bishop of Rome, and, as Apostolic Succession of Saint Peter, is the head of the Catholic Church. The office of the Pope is called the Papacy; his ecclesiastical jurisdiction is called the Holy See or Apostolic See . Early bishops occupying the See of Rome were designated Vicar of Peter; for later popes the more authoritative Vicar of Christ was substituted; this designation was first used by the Roman Synod of 495 to refer to Pope Gelasius I, an
	Popé Pop? (Po'pay) (born ca. 1630 - died ca 1688) was a Tewa religious leader from Ohkay Owingeh (formerly known as San Juan Pueblo), who led the Pueblo Revolt against Spain colonial rule in 1680. He is honored in the U.S. Capitol. Pop? is one of 47 Indigenous peoples of the Americas who were accused, arrested and tried for practicing "Magic (paranormal)" in 1675.
	Pope Alexander VI Pope Alexander VI , born Rodrigo Borja , , is the most controversial of the Secularism popes of the Renaissance and one whose surname became a byword for the debased standards of the papacy of that era. He was born at Xativa, Valncia, Spain, and his father's surname was Lanzol or Llanol; he assumed his mother's family name, Borgia or Borja, on the elevation of his maternal uncle to the papacy as Pope Calixtus III on 8 April 1455.
	Popillia Popillia is a genus of Scarabaeidaes. The most familiar species is the Japanese beetle which is responsible for crop losses around the world, and is near the top of the insect pest lists year after year.
	Poplar Populus is a genus of trees which includes the cottonwoods, poplars, and aspens, all of which are sometimes termed poplars. Poplars are deciduous, and turn bright gold to yellow before their Leaf fall. The leaves of many poplars, including the cottonwoods and aspens, have laterally-flattened stems, so that breezes easily cause the leaves to wobble back and forth, giving the whole tree a "twinkling" appearance in a breeze.
	Popover A popover is a light, hollow roll made from an egg batter similar to that used in making Yorkshire pudding. The name "popover" comes from the fact that the batter swells or "pops" over the top of the muffin tin while baking. They can also be baked in individual custard cups.
	Poppet valve A poppet valve is a valve consisting of a hole, usually round or oval, and a tapered plug, usually a disk shape on the end of a shaft also called a valve stem. The shaft guides the plug portion by sliding through a valve guide. In most applications a pressure differential helps to seal the valve and in some applications also open it.
	Poppy A poppy is any of a number of showy flowers, borne one per Plant stem, belonging to the Papaveraceae. These can be enjoyed in the wild, but are also grown for ornament. There are white, pink, yellow, orange, red and blue poppies; some have a dark centre.
	Poppy mallow The poppy mallow is a genus of nine species in the mallow family, native to the prairies and grasslands of North America. Of the nine species, some are Annual plant and some perennials. Poppy mallow leaf are alternate and palmately lobed. The flowers are cup-shaped and brightly colored.
	Popsicle Popsicle is the most popular brand name in the U.S. and Canada for a brand of ice pop. Popsicle is a trademark owned by Unilever, although it has genericized trademark in North America.
	Popular Front for the Liberation of Palestine The Popular Front for the Liberation of Palestine is a Marxism-Leninism, nationalism Palestinian political and military organization, founded in 1967. It has consistently been the second-largest of the groups forming the Palestinian Liberation Organization, but now has only limited popular support in the Palestinian Territories.
	Population In sociology and biology, a population is the collection of human beings, or organisms of a particular species, living in a given geography area, or space, usually measured by a census. In biology, plant and animal populations are studied, in particular, in a branch of ecology known as population biology, and in population genetics.
	Population growth Population growth is change in population over time, and can be quantified as the change in the number of individuals in a population per unit time. The term population growth can technically refer to any species, but almost always refers to humans, and it is often used informally for the more specific demographics term population growth rate, and is often used to refer specifically to the growth of the World population.
	Populous Populous is a computer and video games developed by Bullfrog Productions in 1989 in video gaming and is regarded by many as being the seminal god game. In 1991 in video gaming, Populous won the Origins Award for Best Military or Strategy Computer Game of 1990 as well as 1990 Computer Game of the Year in American video game magazine Video Games & Computer Entertainment.
	Populus tremuloides Populus tremuloides, the Quaking Aspen or Trembling Aspen, is a deciduous tree native to cooler areas of North America, with the northern limit determined by its intolerance of permafrost. It occurs across Canada in all provinces and territories. In the United States, it occurs at low elevations as far south as northern Nebraska and central Indiana.
	Porbeagle The porbeagle, Lamna nasus, is a large pelagic predatory shark of the family Lamnidae.
	Porcelain Porcelain is a ceramic material made by heating to high temperature selected and refined materials often including clay in the form of kaolinite. One widely recognised definition is from the Combined Nomenclature of the European Communities which states porcelain is completely vitrified, hard, impermeable, white or artificially coloured, translucent and resonant
	Porch A porch is an architecture feature relating to a floor-like platform structure attached to the front or back entrance of a residence. It is external to the walls of the main building proper, but may be enclosed by screen, latticework, broad windows, or other light frame walls extending from the main structure.
	Porcupine This article is about the rodent mammal. For the fictional Marvel Comics character, see Porcupine . Porcupines are rodents best known for their coat of sharp spines, or quills, that defend them from predators. The porcupines include the fourth largest rodent, after the capybara, mara_, and beaver, and are not to be confused with hedgehog which are insectivores.
	Porcupinefish Porcupinefish are fish of the family Diodontidae, , also commonly called blowfish . They are sometimes confused with pufferfish. Porcupinefish are closely related to pufferfishes but porcupinefish have spines on their body. Porcupinefish have the ability to inflate their body by swallowing water and become round like a ball.
	Pork Pork is the meat taken from pigs. While it is one of the most common meats consumed by China, Thailands, Vietnam and Europes, and to some extent North Americans, it is not considered kosher in Judaism or halal under Islamic law.
	Pork and beans Pork and beans is a dish largely thought of as a part of American cuisine. Although its principal ingredient is of Mesoamerican origin, pork and beans no doubt has antecedents in Europe. The recipe varies considerably, but generally consists of navy beans stewed with pork or rendered pork fat.
	Pork pie Pork pie is a traditional United Kingdom food. It consists of pork and pork jelly in a hot water crust pastry and is normally eaten cold. In Yorkshire, a pork pie is occasionally referred to as a 'growler'. There are two main types of pork pie - one of which has the name Melton Mowbray Pork Pie.
	Pornography Pornography, more informally referred to as porn or porno, is the representation of the Human anatomy or Human sexual behavior with the goal of sexual arousal. "The explicit artistic depiction of men and/or women as sexual beings."
	Poroporo Poroporo, also called Kangaroo Apple, is a soft-wooded plant and one of three nightshades native to New Zealand and the eastern coast of Australia. It's an evergreen shrub that can grow up to 12 feet tall. Its hermaphroditic flowers are white to mauve and yield to poisonous berries.
	Porosity Used in geology, hydrogeology, soil science, and building science, the porosity of a porous medium describes how densely the material is packed. It is the proportion of the non-solid volume to the total volume of material, and is defined by the ratio: where Vp is the non-solid volume and Vm is the total volume of material, including the solid and non-solid parts.