1.
Taxonomy (biology)
–
Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
2.
Plant
–
Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. The term is generally limited to the green plants, which form an unranked clade Viridiplantae. This includes the plants, conifers and other gymnosperms, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Green plants have cell walls containing cellulose and obtain most of their energy from sunlight via photosynthesis by primary chloroplasts and their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic and have lost the ability to produce amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although reproduction is also common. There are about 300–315 thousand species of plants, of which the great majority, green plants provide most of the worlds molecular oxygen and are the basis of most of Earths ecologies, especially on land. Plants that produce grains, fruits and vegetables form humankinds basic foodstuffs, Plants play many roles in culture. They are used as ornaments and, until recently and in variety, they have served as the source of most medicines. The scientific study of plants is known as botany, a branch of biology, Plants are one of the two groups into which all living things were traditionally divided, the other is animals. The division goes back at least as far as Aristotle, who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food. Much later, when Linnaeus created the basis of the system of scientific classification. Since then, it has become clear that the plant kingdom as originally defined included several unrelated groups, however, these organisms are still often considered plants, particularly in popular contexts. When the name Plantae or plant is applied to a group of organisms or taxon. The evolutionary history of plants is not yet settled. Those which have been called plants are in bold, the way in which the groups of green algae are combined and named varies considerably between authors. Algae comprise several different groups of organisms which produce energy through photosynthesis, most conspicuous among the algae are the seaweeds, multicellular algae that may roughly resemble land plants, but are classified among the brown, red and green algae. Each of these groups also includes various microscopic and single-celled organisms
3.
Pinophyta
–
The Pinophyta, also known as Coniferophyta or Coniferae, or commonly as conifers, are a division of vascular land plants containing a single class, Pinopsida. They are gymnosperms, cone-bearing seed plants, all extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs, examples include cedars, Douglas firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews. As of 1998, the division Pinophyta was estimated to contain eight families,68 genera, although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere, boreal conifers have many wintertime adaptations. The narrow conical shape of northern conifers, and their downward-drooping limbs, many of them seasonally alter their biochemistry to make them more resistant to freezing. While tropical rainforests have more biodiversity and turnover, the conifer forests of the world represent the largest terrestrial carbon sink. Conifers are of economic value for softwood lumber and paper production. The earliest conifers in the record date to the late Carboniferous period, possibly arising from Cordaites. Pinophytes, Cycadophytes, and Ginkgophytes all developed at this time, an important adaptation of these gymnosperms was allowing plants to live without being so dependent on water. Other adaptations are pollen and the seed, which allows the embryo to be transported and developed elsewhere, Conifers appear to be one of the taxa that benefited from the Permian–Triassic extinction event, and were the dominant land plants of the Mesozoic. They were overtaken by the plants, which first appeared in the Cretaceous. They were the food of herbivorous dinosaurs, and their resins and poisons would have given protection against herbivores. Reproductive features of modern conifers had evolved by the end of the Mesozoic era, Conifer is a Latin word, a compound of conus and ferre, meaning the one that bears cone. A descriptive name in use for the conifers is Coniferae. Alternatively, descriptive botanical names may also be used at any rank above family and this means that if conifers are considered a division, they may be called Pinophyta or Coniferae. As a class they may be called Pinopsida or Coniferae, as an order they may be called Pinales or Coniferae or Coniferales. Conifers are the largest and economically most important component group of the gymnosperms, the division Pinophyta consists of just one class, Pinopsida, which includes both living and fossil taxa
4.
Pine
–
A pine is any conifer in the genus Pinus, /ˈpiːnuːs/, of the family Pinaceae. Pinus is the genus in the subfamily Pinoideae. The Plant List compiled by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts 126 species names of pines as current, together with 35 unresolved species, the modern English name pine derives from Latin pinus, which some have traced to the Indo-European base *pīt- ‘resin’. Before the 19th century, pines were often referred to as firs, the genus is divided into three subgenera, which can be distinguished by cone, seed, and leaf characters, Pinus subg. Pinus, the yellow, or hard pine group, generally harder wood. Ducampopinus, the foxtail or pinyon group Pinus subg, strobus, the white, or soft pine group, generally with softer wood and five needles per fascicle Most regions of the Northern Hemisphere host some native species of pines. One species crosses the equator in Sumatra to 2°S, in North America, various species occur in regions at latitudes from as far north as 66°N to as far south as 12°N. Various species have been introduced to temperate and subtropical regions of both hemispheres, where they are grown as timber or cultivated as ornamental plants in parks, a number of such introduced species have become invasive and threaten native ecosystems. Pine trees are evergreen, coniferous trees growing 3–80 m tall. The smallest are Siberian dwarf pine and Potosi pinyon, and the tallest is a 81.79 m tall ponderosa pine located in southern Oregons Rogue River-Siskiyou National Forest, the bark of most pines is thick and scaly, but some species have thin, flaky bark. The branches are produced in regular pseudo whorls, actually a very tight spiral, the spiral growth of branches, needles, and cone scales are arranged in Fibonacci number ratios. The new spring shoots are sometimes called candles, they are covered in brown or whitish bud scales and point upward at first, then turn green. These candles offer foresters a means to evaluate fertility of the soil, pines are long-lived, and typically reach ages of 100–1,000 years, some even more. The longest-lived is the Great Basin bristlecone pine, Pinus longaeva, one individual of this species, dubbed Methuselah, is one of the worlds oldest living organisms at around 4,600 years old. This tree can be found in the White Mountains of California, an older tree, now cut down, was dated at 4,900 years old. It was discovered in a grove beneath Wheeler Peak and it is now known as Prometheus after the Greek immortal, pines have four types of leaf, Seed leaves on seedlings, born in a whorl of 4–24. Juvenile leaves, which follow immediately on seedlings and young plants, 2–6 cm long, single, green or often blue-green and these are produced for six months to five years, rarely longer. Scale leaves, similar to bud scales, small, brown and non-photosynthetic, needles, the adult leaves, are green and bundled in clusters called fascicles
5.
Carl Linnaeus
–
Carl Linnaeus, also known after his ennoblement as Carl von Linné, was a Swedish botanist, physician, and zoologist, who formalised the modern system of naming organisms called binomial nomenclature. He is known by the father of modern taxonomy. Many of his writings were in Latin, and his name is rendered in Latin as Carolus Linnæus, Linnaeus was born in the countryside of Småland, in southern Sweden. He received most of his education at Uppsala University. He lived abroad between 1735 and 1738, where he studied and also published a first edition of his Systema Naturae in the Netherlands and he then returned to Sweden, where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on journeys through Sweden to find and classify plants. In the 1750s and 1760s, he continued to collect and classify animals, plants, and minerals, at the time of his death, he was one of the most acclaimed scientists in Europe. The philosopher Jean-Jacques Rousseau sent him the message, Tell him I know no man on earth. The German writer Johann Wolfgang von Goethe wrote, With the exception of Shakespeare and Spinoza, Swedish author August Strindberg wrote, Linnaeus was in reality a poet who happened to become a naturalist. Among other compliments, Linnaeus has been called Princeps botanicorum, The Pliny of the North and he is also considered as one of the founders of modern ecology. In botany, the abbreviation used to indicate Linnaeus as the authority for species names is L. In older publications, sometimes the abbreviation Linn. is found, Linnæus was born in the village of Råshult in Småland, Sweden, on 23 May 1707. He was the first child of Nicolaus Ingemarsson and Christina Brodersonia and his siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, and Emerentia Linnæa. One of a line of peasants and priests, Nils was an amateur botanist, a Lutheran minister. Christina was the daughter of the rector of Stenbrohult, Samuel Brodersonius, a year after Linnæus birth, his grandfather Samuel Brodersonius died, and his father Nils became the rector of Stenbrohult. The family moved into the rectory from the curates house, even in his early years, Linnæus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and often showed flowers to Linnaeus, soon Linnæus was given his own patch of earth where he could grow plants
6.
Texas
–
Texas is the second largest state in the United States by both area and population. Other major cities include Austin, the second most populous state capital in the U. S. Texas is nicknamed the Lone Star State to signify its former status as an independent republic, and as a reminder of the states struggle for independence from Mexico. The Lone Star can be found on the Texan state flag, the origin of Texass name is from the word Tejas, which means friends in the Caddo language. Due to its size and geologic features such as the Balcones Fault, although Texas is popularly associated with the U. S. southwestern deserts, less than 10 percent of Texas land area is desert. Most of the centers are located in areas of former prairies, grasslands, forests. Traveling from east to west, one can observe terrain that ranges from coastal swamps and piney woods, to rolling plains and rugged hills, the term six flags over Texas refers to several nations that have ruled over the territory. Spain was the first European country to claim the area of Texas, Mexico controlled the territory until 1836 when Texas won its independence, becoming an independent Republic. In 1845, Texas joined the United States as the 28th state, the states annexation set off a chain of events that caused the Mexican–American War in 1846. A slave state before the American Civil War, Texas declared its secession from the U. S. in early 1861, after the Civil War and the restoration of its representation in the federal government, Texas entered a long period of economic stagnation. One Texan industry that thrived after the Civil War was cattle, due to its long history as a center of the industry, Texas is associated with the image of the cowboy. The states economic fortunes changed in the early 20th century, when oil discoveries initiated a boom in the state. With strong investments in universities, Texas developed a diversified economy, as of 2010 it shares the top of the list of the most Fortune 500 companies with California at 57. With a growing base of industry, the leads in many industries, including agriculture, petrochemicals, energy, computers and electronics, aerospace. Texas has led the nation in export revenue since 2002 and has the second-highest gross state product. The name Texas, based on the Caddo word tejas meaning friends or allies, was applied by the Spanish to the Caddo themselves, during Spanish colonial rule, the area was officially known as the Nuevo Reino de Filipinas, La Provincia de Texas. Texas is the second largest U. S. state, behind Alaska, though 10 percent larger than France and almost twice as large as Germany or Japan, it ranks only 27th worldwide amongst country subdivisions by size. If it were an independent country, Texas would be the 40th largest behind Chile, Texas is in the south central part of the United States of America. Three of its borders are defined by rivers, the Rio Grande forms a natural border with the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the south
7.
Florida
–
Florida /ˈflɒrᵻdə/ is a state located in the southeastern region of the United States. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia, to the east by the Atlantic Ocean, Florida is the 22nd-most extensive, the 3rd-most populous, and the 8th-most densely populated of the U. S. states. Jacksonville is the most populous municipality in the state and is the largest city by area in the contiguous United States, the Miami metropolitan area is Floridas most populous urban area. The city of Tallahassee is the state capital, much of the state is at or near sea level and is characterized by sedimentary soil. The climate varies from subtropical in the north to tropical in the south, the American alligator, American crocodile, Florida panther, and manatee can be found in the Everglades National Park. It was a location of the Seminole Wars against the Native Americans. Today, Florida is distinctive for its large Cuban expatriate community and high population growth, the states economy relies mainly on tourism, agriculture, and transportation, which developed in the late 19th century. Florida is also renowned for amusement parks, orange crops, the Kennedy Space Center, Florida has attracted many writers such as Marjorie Kinnan Rawlings, Ernest Hemingway and Tennessee Williams, and continues to attract celebrities and athletes. It is internationally known for golf, tennis, auto racing, by the 16th century, the earliest time for which there is a historical record, major Native American groups included the Apalachee, the Timucua, the Ais, the Tocobaga, the Calusa and the Tequesta. Florida was the first part of the continental United States to be visited and settled by Europeans, the earliest known European explorers came with the Spanish conquistador Juan Ponce de León. Ponce de León spotted and landed on the peninsula on April 2,1513 and he named the region La Florida. The story that he was searching for the Fountain of Youth is a myth, in May 1539, Conquistador Hernando de Soto skirted the coast of Florida, searching for a deep harbor to land. He described seeing a wall of red mangroves spread mile after mile, some reaching as high as 70 feet. Very soon, many smokes appeared along the whole coast, billowing against the sky, the Spanish introduced Christianity, cattle, horses, sheep, the Spanish language, and more to Florida. Both the Spanish and French established settlements in Florida, with varying degrees of success, in 1559, Don Tristán de Luna y Arellano established a settlement at present-day Pensacola, making it the first attempted settlement in Florida, but it was abandoned by 1561. Spain maintained tenuous control over the region by converting the tribes to Christianity. The area of Spanish Florida diminished with the establishment of English settlements to the north, the English attacked St. Augustine, burning the city and its cathedral to the ground several times. Florida attracted numerous Africans and African-Americans from adjacent British colonies who sought freedom from slavery, in 1738, Governor Manuel de Montiano established Fort Gracia Real de Santa Teresa de Mose near St
8.
Delaware
–
Delaware is a state located in the Mid-Atlantic and/or Northeastern regions of the United States. It is bordered to the south and west by Maryland, to the northeast by New Jersey, the state takes its name from Thomas West, 3rd Baron De La Warr, an English nobleman and Virginias first colonial governor. Delaware occupies the portion of the Delmarva Peninsula and is the second smallest, the sixth least populous. Delaware is divided into three counties, the lowest number of counties of any state, from north to south, the three counties are New Castle, Kent, and Sussex. While the southern two counties have historically been agricultural, New Castle County has been more industrialized. Before its coastline was explored by Europeans in the 16th century, Delaware was inhabited by groups of Native Americans, including the Lenape in the north. It was initially colonized by Dutch traders at Zwaanendael, near the present town of Lewes, Delaware was one of the 13 colonies participating in the American Revolution. On December 7,1787, Delaware became the first state to ratify the Constitution of the United States, the Delaware Indians, a name used by Europeans for Lenape people indigenous to the Delaware Valley, also derive their name from the same source. The surname de La Warr comes from Sussex and is of Anglo-Norman origin and it came probably from a Norman lieu-dit La Guerre. This toponymic could derive from the Latin word ager, from the Breton gwern or from the Late Latin varectum, the toponyms Gara, Gare, Gaire also appear in old texts cited by Lucien Musset, where the word gara means gore. It could also be linked with a patronymic from the Old Norse verr, Delaware is 96 miles long and ranges from 9 miles to 35 miles across, totaling 1,954 square miles, making it the second-smallest state in the United States after Rhode Island. Delaware is bounded to the north by Pennsylvania, to the east by the Delaware River, Delaware Bay, New Jersey and the Atlantic Ocean, small portions of Delaware are also situated on the eastern side of the Delaware River sharing land boundaries with New Jersey. The state of Delaware, together with the Eastern Shore counties of Maryland, the definition of the northern boundary of the state is unusual. Most of the boundary between Delaware and Pennsylvania was originally defined by an arc extending 12 miles from the cupola of the courthouse in the city of New Castle and this boundary is often referred to as the Twelve-Mile Circle. This is the only nominally circular state boundary in the United States, to the west, a portion of the arc extends past the easternmost edge of Maryland. The remaining western border runs slightly east of due south from its intersection with the arc, the Wedge of land between the northwest part of the arc and the Maryland border was claimed by both Delaware and Pennsylvania until 1921, when Delawares claim was confirmed. Delaware is on a plain, with the lowest mean elevation of any state in the nation. Its highest elevation, located at Ebright Azimuth, near Concord High School, the northernmost part of the state is part of the Piedmont Plateau with hills and rolling surfaces
9.
New Jersey
–
New Jersey is a state in the Northeastern and mid-Atlantic regions of the United States. It is bordered on the north and east by New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania, New Jersey is the fourth-smallest state but the 11th-most populous and the most densely populated of the 50 United States. New Jersey lies entirely within the statistical areas of New York City. New Jersey was inhabited by Native Americans for more than 2,800 years, in the early 17th century, the Dutch and the Swedes made the first European settlements. New Jersey was the site of decisive battles during the American Revolutionary War in the 18th century. In the 19th century, factories in cities such as Camden, Paterson, Newark, Trenton, around 180 million years ago, during the Jurassic Period, New Jersey bordered North Africa. The pressure of the collision between North America and Africa gave rise to the Appalachian Mountains, around 18,000 years ago, the Ice Age resulted in glaciers that reached New Jersey. As the glaciers retreated, they left behind Lake Passaic, as well as rivers, swamps. New Jersey was originally settled by Native Americans, with the Lenni-Lenape being dominant at the time of contact, scheyichbi is the Lenape name for the land that is now New Jersey. The Lenape society was divided into clans that were based upon common female ancestors. These clans were organized into three distinct phratries identified by their animal sign, Turtle, Turkey, and Wolf and they first encountered the Dutch in the early 17th century, and their primary relationship with the Europeans was through fur trade. The Dutch became the first Europeans to lay claim to lands in New Jersey, the Dutch colony of New Netherland consisted of parts of modern Middle Atlantic states. Although the European principle of ownership was not recognized by the Lenape. The first to do so was Michiel Pauw who established a patronship called Pavonia in 1630 along the North River which eventually became the Bergen, peter Minuits purchase of lands along the Delaware River established the colony of New Sweden. During the English Civil War, the Channel Island of Jersey remained loyal to the British Crown and it was from the Royal Square in St. Helier that Charles II of England was proclaimed King in 1649, following the execution of his father, Charles I. The North American lands were divided by Charles II, who gave his brother, the Duke of York, the region between New England and Maryland as a proprietary colony. James then granted the land between the Hudson River and the Delaware River to two friends who had remained loyal through the English Civil War, Sir George Carteret and Lord Berkeley of Stratton, the area was named the Province of New Jersey. Since the states inception, New Jersey has been characterized by ethnic, New England Congregationalists settled alongside Scots Presbyterians and Dutch Reformed migrants
10.
Acer rubrum
–
Acer rubrum is one of the most common and widespread deciduous trees of eastern and central North America. The U. S. Forest service recognizes it as the most abundant native tree in eastern North America. The red maple ranges from southeastern Manitoba around the Lake of the Woods on the border with Ontario and Minnesota, east to Newfoundland, south to Florida, many of its features, especially its leaves, are quite variable in form. At maturity it often attains a height of around 15 m and its flowers, petioles, twigs and seeds are all red to varying degrees. Among these features, however, it is best known for its brilliant deep scarlet foliage in autumn, over most of its range, red maple is adaptable to a very wide range of site conditions, perhaps more so than any other tree in eastern North America. It can be found growing in swamps, on dry soils. It grows well from sea level to about 900 m, due to its attractive fall foliage and pleasing form, it is often used as a shade tree for landscapes. It is used commercially on a scale for maple syrup production as well as for its medium to high quality lumber. It is also the State Tree of Rhode Island, the red maple can be considered weedy or invasive. It is taking over forests in the eastern US, replacing traditional mainstays like oaks, though A. rubrum is usually easy to identify, it is highly changeable in morphological characteristics. It is a medium to large sized tree, reaching heights of 18 to 27 metres, the leaves are usually 9 to 11 centimetres long on a full grown tree. The trunk diameter can range from 46 to 76 cm, depending on the growing conditions and its spread is about 12 m. A 10-year-old sapling will stand about 6 m tall, in forests, the bark will remain free of branches until some distance up the tree. Individuals grown in the open are shorter and thicker with a rounded crown. Generally speaking, however, the crown is irregularly ovoid with ascending whip-like curved shoots, the bark is a pale grey and smooth when the individual is young. As the tree grows the bark becomes darker and cracks into slightly raised long plates, the largest known living red maple is located near Armada, Michigan, at a height of 38.1 m and a bole circumference, at breast height, of 4.95 m. The leaves of the red maple offer the easiest way to distinguish it from its relatives, as with nearly all North American maple trees, they are deciduous and arranged oppositely on the twig. They are typically 5–10 cm long and wide with 3-5 palmate lobes with a serrated margin, the sinuses are typically narrow, but the leaves can exhibit considerable variation
11.
Lumber
–
Lumber, or timber is wood that has been processed into beams and planks, a stage in the process of wood production. Lumber may also refer to currently un-needed furniture, as in Lumber room, or an awkward gait, ultimately derived from the look of unfashionable, Lumber may be supplied either rough-sawn, or surfaced on one or more of its faces. Besides pulpwood, rough lumber is the raw material for furniture-making and it is available in many species, usually hardwoods, but it is also readily available in softwoods, such as white pine and red pine, because of their low cost. Lumber is mainly used for structural purposes but has other uses as well. It is classified more commonly as a softwood than as a hardwood, in Australia, Ireland, New Zealand and Britain, the term timber describes sawn wood products, such as floor boards. In the United States and Canada, generally timber describes standing or felled trees, before they are milled into boards, Timber there also describes sawn lumber not less than 5 inches in its smallest dimension. The latter includes the often partly finished lumber used in timber-frame construction, remanufactured lumber is the result of secondary or tertiary processing/cutting of previously milled lumber. Specifically, it is cut for industrial or wood-packaging use. Lumber is cut by ripsaw or resaw to create dimensions that are not usually processed by a primary sawmill, resawing is the splitting of 1-inch through 12-inch hardwood or softwood lumber into two or more thinner pieces of full-length boards. For example, splitting a ten-foot 2×4 into two ten-foot 1×4s is considered resawing, structural lumber may also be produced from recycled plastic and new plastic stock. Its introduction has been opposed by the forestry industry. Blending fiberglass in plastic lumber enhances its strength, durability, logs are converted into timber by being sawn, hewn, or split. Sawing with a rip saw is the most common method, because sawing allows logs of lower quality, with grain and large knots. There are various types of sawing, Plain sawn —A log sawn through without adjusting the position of the log, quarter sawn and rift sawn—These terms have been confused in history but generally mean lumber sawn so the annual rings are reasonably perpendicular to the sides of the lumber. Boxed heart—The pith remains within the piece with some allowance for exposure, heart center—the center core of a log. Free of heart center —A side-cut timber without any pith, free of knots —No knots are present. Dimensional lumber is lumber that is cut to standardized width and depth, carpenters extensively use dimensional lumber in framing wooden buildings. Common sizes include 2×4, 2×6, and 4×4, the length of a board is usually specified separately from the width and depth
12.
Axolotl
–
The axolotl also known as a Mexican salamander or a Mexican walking fish, is a neotenic salamander, closely related to the tiger salamander. Although the axolotl is colloquially known as a fish, it is not a fish. The species originates from numerous lakes, such as Lake Xochimilco underlying Mexico City, axolotls are unusual among amphibians in that they reach adulthood without undergoing metamorphosis. Instead of developing lungs and taking to land, the adults remain aquatic, axolotls should not be confused with waterdogs, the larval stage of the closely related tiger salamanders, which are widespread in much of North America and occasionally become neotenic. Neither should they be confused with mudpuppies, fully aquatic salamanders which are not closely related to the axolotl, as of 2010, wild axolotls were near extinction due to urbanization in Mexico City and consequent water pollution. They are currently listed by CITES as a species and by IUCN as critically endangered in the wild. Axolotls are used extensively in research due to their ability to regenerate limbs. Axolotls were also sold as food in Mexican markets and were a staple in the Aztec diet, a four-month-long search in 2013 turned up no surviving individuals in the wild. Previous surveys in 1998,2003 and 2008 had found 6,000,1,000 and 100 axolotls per square kilometer in its Lake Xochimilco habitat, respectively. A sexually mature adult axolotl, at age 18–24 months, ranges in length from 15–45 cm, although a close to 23 cm is most common. Axolotls possess features typical of larvae, including external gills. Their heads are wide, and their eyes are lidless and their limbs are underdeveloped and possess long, thin digits. Males are identified by their swollen cloacae lined with papillae, while females are noticeable for their bodies full of eggs. Three pairs of external gill stalks originate behind their heads and are used to move oxygenated water, the external gill rami are lined with filaments to increase surface area for gas exchange. Four gill slits lined with gill rakers are hidden underneath the external gills, axolotls have barely visible vestigial teeth, which would have developed during metamorphosis. The primary method of feeding is by suction, during which their rakers interlock to close the gill slits, external gills are used for respiration, although buccal pumping may also be used to provide oxygen to their lungs. Axolotls have four pigmentation genes which when mutated create different color variants, the normal wild type animal is brown/tan with gold speckles and an olive undertone. The four mutant colors are leucistic, albino, axanthic and melanoid, axolotls also have some limited ability to alter their color to provide better camouflage by changing the relative size and thickness of their melanophores
. PMID 24653210.
Data related to Pinus taeda at Wikispecies
Media related to Pinus taeda at Wikimedia Commons
