Misplaced Pages

#484515

85-643: The log cabin was constructed in three days in May 1703, by soldiers of the Semyonovskiy Regiment . At that time, the new St. Petersburg was described as "a heap of villages linked together, like some plantation in the West Indies". The design is a combination of an izba , a traditional Russian countryside house typical of the 17th century, and the Tsar's beloved Dutch Baroque , later to evolve into

170-720: A basic form of log construction was used all over North Europe and Asia and later imported to America. Log construction was especially suited to Scandinavia, where straight, tall tree trunks ( pine and spruce ) are readily available. With suitable tools, a log cabin can be erected from scratch in days by a family. As no chemical reaction is involved, such as hardening of mortar, a log cabin can be erected in any weather or season. Many older towns in Northern Scandinavia have been built exclusively out of log houses, which have been decorated by board paneling and wood cuttings. Today, construction of modern log cabins as leisure homes

255-607: A broad range of mortar or other infill materials used between the logs in the construction of log cabins and other log-walled structures. Traditionally, dried mosses, such as Pleurozium schreberi or Hylocomium splendens , were used in the Nordic countries as an insulator between logs. In the United States, Chinks were small stones or wood or corn cobs stuffed between the logs. In the United States, settlers may have first constructed log cabins by 1640. Historians believe that

340-741: A bust of Peter by Parmen Zabello stands outside. The cabin is open to the public as a branch of the Russian Museum . Notes Citations Bibliography 59°57′12″N 30°19′51″E  /  59.9533°N 30.3308°E  / 59.9533; 30.3308 Log cabin A log cabin is a small log house , especially a minimally finished or less architecturally sophisticated structure. Log cabins have an ancient history in Europe, and in America are often associated with first-generation home building by settlers. Construction with logs

425-407: A few years of exposure to wind and rain. Materials which are porous and moisture retentive, such as brick , wood , and certain coarse concrete mixtures, are hospitable to moss. Surfaces can also be prepared with acidic substances, including buttermilk , yogurt , urine , and gently puréed mixtures of moss samples, water and ericaceous compost . In the cool, humid, cloudy Pacific Northwest , moss

510-926: A garden weed in Vancouver and Seattle areas; Bryum argenteum , the cosmopolitan sidewalk moss, and Ceratodon purpureus , red roof moss, another cosmopolitan species. A few species are wholly aquatic, such as Fontinalis antipyretica , common water moss; and others such as Sphagnum inhabit bogs, marshes and very slow-moving waterways. Such aquatic or semi-aquatic mosses can greatly exceed the normal range of lengths seen in terrestrial mosses. Individual plants 20–30 cm (8–12 in) or more long are common in Sphagnum species for example. But even aquatic species of moss and other bryophytes needs their mature capsules to be exposed to air by seta elongation or seasonal lowering of water level to be able to reproduce. Wherever they occur, mosses require liquid water for at least part of

595-408: A haploid spore that germinates to produce a protonema ( pl. protonemata), which is either a mass of thread-like filaments or thalloid (flat and thallus-like). Massed moss protonemata typically look like a thin green felt, and may grow on damp soil, tree bark, rocks, concrete, or almost any other reasonably stable surface. This is a transitory stage in the life of a moss, but from the protonema grows

680-415: A log cabin tends to compress slightly as it settles, over a few months or years. Nails would soon be out of alignment and torn out. Log cabins were largely built from logs laid horizontally and interlocked on the ends with notches. Some log cabins were built without notches and simply nailed together, but this was not as structurally sound. The most important aspect of cabin building is the site upon which

765-472: A love of forests, and they ended up living alongside and even culturally assimilating with them (they are the earlier and lesser-known Findian tribe, being overshadowed by the Ojibwe Findians of Minnesota, Michigan and Ontario, Canada). In those forests, the first log cabins of America were built, using traditional Finnish methods. Even though New Sweden existed only briefly before it was absorbed by

850-536: A member of the Polytrichidae is probably Dawsonia superba , a native to New Zealand and other parts of Australasia . The fossil record of moss is sparse, due to their soft-walled and fragile nature. Unambiguous moss fossils have been recovered from as early as the Permian of Antarctica and Russia, and a case has been made for Carboniferous mosses. It has further been claimed that tube-like fossils from

935-451: A memorial to his modesty, and the creation of St. Petersburg ex nihilo . Catherine the Great ordered the shelter for the cabin to be renovated in 1784, and the protective brick pavilion was reconstructed by Nicholas I in the 1840s. Peter's domiki were used to mark significant dates, such as the bicentenary of Peter's birth in 1672. They became a centre of devotion to the tsar ,

SECTION 10

#1732780390485

1020-414: A partner that contains the same, or similar, genetic information. By contrast, mosses and other bryophytes have only a single set of chromosomes and so are haploid (i.e. each chromosome exists in a unique copy within the cell). There is a period in the moss life cycle when they do have a double set of paired chromosomes, but this happens only during the sporophyte stage. The moss life-cycle starts with

1105-674: A popular type of barn found throughout the American Southern and Southeastern regions . Crib barns were especially ubiquitous in the Appalachian and Ozark Mountain states of North Carolina , Virginia , Kentucky , Tennessee , and Arkansas . In Europe , modern log cabins are often built in gardens and used as summerhouses, home offices, or as an additional room in the garden. Summer houses and cottages are often built from logs in Northern Europe . Chinking refers to

1190-438: A scent-mediated relationship analogous to the plant-pollinator relationship found in many seed plants. The stinkmoss species Splachnum sphaericum develops insect pollination further by attracting flies to its sporangia with a strong smell of carrion, and providing a strong visual cue in the form of red-coloured swollen collars beneath each spore capsule. Flies attracted to the moss carry its spores to fresh herbivore dung, which

1275-412: A similar purpose. Mosses can be either dioicous (compare dioecious in seed plants) or monoicous (compare monoecious ). In dioicous mosses, male and female sex organs are borne on different gametophyte plants. In monoicous (also called autoicous) mosses, both are borne on the same plant. In the presence of water, sperm from the antheridia swim to the archegonia and fertilisation occurs, leading to

1360-433: A small gabled-roof cabin of round logs with an opening in the roof to vent smoke, to more sophisticated squared logs with interlocking double-notch joints, the timber extending beyond the corners. Log saunas or bathhouses of this type are still found in rural Finland. By stacking tree trunks one on top of another and overlapping the logs at the corners, people made the "log cabin". They developed interlocking corners by notching

1445-842: A variety of notches. One method common in the Ohio River Valley in Southwestern Ohio and Southeastern Indiana is the block house end method, which is exemplified in the David Brown House in Rising Sun, Indiana . Some older buildings in the Midwestern United States and the Canadian Prairies are log structures covered with clapboards or other materials. 19th-century cabins used as dwellings were occasionally plastered on

1530-463: Is a fully developed industry in Finland and Sweden. Modern log cabins often feature fiberglass insulation and are sold as prefabricated kits machined in a factory, rather than hand-built in the field like ancient log cabins. Log cabins are mostly constructed without the use of nails and thus derive their stability from simple stacking, with only a few dowel joints for reinforcement. This is because

1615-435: Is deliberately encouraged to grow under aesthetic principles exemplified by Japanese gardening . In old temple gardens, moss can carpet a forest scene. Moss is thought to add a sense of calm, age, and stillness to a garden scene. Moss is also used in bonsai to cover the soil and enhance the impression of age. Rules of cultivation are not widely established. Moss collections are quite often begun using samples transplanted from

1700-448: Is disrupted by fungal chitin . Galotto et al. , 2020 applied chitooctaose and found that tips detected and responded to this chitin derivative by changing gene expression . They concluded that this defense response was probably conserved from the most recent common ancestor of bryophytes and tracheophytes . Orr et al. , 2020 found that the microtubules of growing tip cells were structurally similar to F-actin and served

1785-545: Is famous for its moss garden. The moss garden was created by removing shrubby underbrush and herbaceous groundcovers, thinning trees, and allowing mosses to fill in naturally. Mosses are sometimes used in green roofs . Advantages of mosses over higher plants in green roofs include reduced weight loads, increased water absorption, no fertilizer requirements, and high drought tolerance. Since mosses do not have true roots, they require less planting medium than higher plants with extensive root systems. With proper species selection for

SECTION 20

#1732780390485

1870-446: Is positively associated with the presence of dwarf males in several phyllodioicous species. Dwarf males occur in several unrelated lineages and may be more common than previously thought. For example, it is estimated that between one quarter and half of all dioicous pleurocarps have dwarf males. The moss Physcomitrium patens has been used as a model organism to study how plants repair damage to their DNA, especially

1955-504: Is sometimes allowed to grow naturally as a moss lawn , one that needs little or no mowing, fertilizing or watering. In this case, grass is considered to be the weed. Landscapers in the Seattle area sometimes collect boulders and downed logs growing mosses for installation in gardens and landscapes. Woodland gardens in many parts of the world can include a carpet of natural mosses. The Bloedel Reserve on Bainbridge Island, Washington State,

2040-534: Is the dominant phase of the life cycle . This contrasts with the pattern in all vascular plants ( seed plants and pteridophytes ), where the diploid sporophyte generation is dominant. Mosses reproduce using spores , not seeds , and have no flowers. Moss gametophytes have stems which may be simple or branched and upright (acrocarp) or prostrate (pleurocarp). The early divergent classes Takakiopsida, Sphagnopsida, Andreaeopsida and Andreaeobryopsida either lack stomata or have pseudostomata that do not form pores. In

2125-545: Is the favoured habitat of the species of this genus. In many mosses, e.g., Ulota phyllantha , green vegetative structures called gemmae are produced on leaves or branches, which can break off and form new plants without the need to go through the cycle of fertilization. This is a means of asexual reproduction , and the genetically identical units can lead to the formation of clonal populations. Moss dwarf males (also known as nannandry or phyllodioicy ) originate from wind-dispersed male spores that settle and germinate on

2210-533: The 1952 presidential election in a landslide to Dwight D. Eisenhower . A popular children's toy in the United States is Lincoln Logs , which are various notched dowel rods that can be fitted together to build scale miniature-sized structures. Moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta ( / b r aɪ ˈ ɒ f ə t ə / , / ˌ b r aɪ . ə ˈ f aɪ t ə / ) sensu stricto . Bryophyta ( sensu lato , Schimp . 1879 ) may also refer to

2295-625: The Petrine Baroque . Peter built similar domiki elsewhere in Russia - for example, in Voronezh , and Vologda . The wooden cabin in St. Petersburg covers only 60 square metres (650 sq ft) and contains three rooms - living room, bedroom, and study. It has large ornate windows and a high hipped roof of wooden tiles. Inside, the wooden walls were painted with red oil to resemble brick, and

2380-767: The Russian Orthodox Church , and the Russian motherland ( rodina ). A prized national monument, the contents were removed, and the Cabin was boarded up and camouflaged during the Second World War . It was the first St. Petersburg museum to reopen in September 1944, after the end of the Siege of Leningrad . Personal and domestic objects owned and used by Peter are still displayed within, and

2465-558: The Silurian are the macerated remains of moss calyptræ . Mosses also appear to evolve 2–3 times slower than ferns, gymnosperms and angiosperms . Recent research shows that ancient moss could explain why the Ordovician ice ages occurred. When the ancestors of today's moss started to spread on land 470 million years ago, they absorbed CO 2 from the atmosphere and extracted minerals by secreting organic acids that dissolved

2550-475: The Southern Hemisphere . Some naturalists feel that mosses grow on the damper side of trees and rocks. In some cases, such as sunny climates in temperate northern latitudes, this will be the shaded north side of the tree or rock. On steep slopes, it may be the uphill side. For mosses that grow on tree branches, this is generally the upper side of the branch on horizontally growing sections or near

2635-408: The gametophore ("gamete-bearer") that is structurally differentiated into stems and leaves. A single mat of protonemata may develop several gametophore shoots, resulting in a clump of moss. From the tips of the gametophore stems or branches develop the sex organs of the mosses. The female organs are known as archegonia ( sing. archegonium ) and are protected by a group of modified leaves known as

Cabin of Peter the Great - Misplaced Pages Continue

2720-410: The polysporangiophytes , which include all vascular plants. The spore-producing sporophytes (i.e. the diploid multicellular generation) are short-lived and usually capable of photosynthesis, but are dependent on the gametophyte for water supply and most or all of its nutrients. Also, in the majority of mosses, the spore-bearing capsule enlarges and matures after its stalk elongates, while in liverworts

2805-533: The 18th century still stand, but they were often not intended as permanent dwellings. Possibly the oldest surviving log house in the United States is the C. A. Nothnagle Log House ( c.  1640 ) in New Jersey. Settlers often built log cabins as temporary homes to live in while constructing larger, permanent houses; then they either demolished the log structures or used them as outbuildings, such as barns or chicken coops . Log cabins were sometimes hewn on

2890-637: The Dutch colony of New Netherland , which was eventually taken over by the English, these quick and easy construction techniques of the Finns not only remained, but spread. Germans and Ukrainians also used this technique. The contemporaneous British settlers had no tradition of building with logs, but they quickly adopted the method. The first English settlers did not widely use log cabins, building in forms more traditional to them. Few log cabins dating from

2975-502: The atmosphere. Small organisms feeding on the nutrients created large areas without oxygen, which caused a mass extinction of marine species, while the levels of CO 2 dropped all over the world, allowing the formation of ice caps on the poles. Moss gametophytes are autotrophic and require sunlight to perform photosynthesis . Shade tolerance varies by species, just as it does with higher plants. In most areas, mosses grow chiefly in moist, shaded areas, such as wooded areas and at

3060-535: The cabin was built. Site selection was aimed at providing the cabin inhabitants with both sunlight and drainage to make them better able to cope with the rigors of frontier life. Proper site selection placed the home in a location best suited to manage the farm or ranch. When the first pioneers built cabins, they were able to "cherry pick" the best logs for cabins. These were old-growth trees with few limbs (knots) and straight with little taper. Such logs did not need to be hewn to fit well together. Careful notching minimized

3145-405: The cabin. The decision about roof type often was based on the material for roofing like bark. Milled lumber was usually the most popular choice for rafter roofs in areas where it was available. These roofs typify many log cabins built in the 20th century, having full-cut 2×4 rafters covered with pine and cedar shingles. The purlin roofs found in rural settings and locations, where milled lumber

3230-430: The capsule enlarges and matures before its stalk elongates. Other differences are not universal for all mosses and all liverworts, but the presence of a clearly differentiated stem with simple-shaped, non-vascular leaves that are not arranged in three ranks, all point to the plant being a moss. Vascular plants have two sets of chromosomes in their vegetative cells and are said to be diploid , i.e. each chromosome has

3315-407: The capsule is mature. Within the capsule, spore-producing cells undergo meiosis to form haploid spores, upon which the cycle can start again. The mouth of the capsule is usually ringed by a set of teeth called peristome. This may be absent in some mosses. Most mosses rely on the wind to disperse the spores. In the genus Sphagnum the spores are projected about 10–20 cm (4–8 in) off

3400-400: The characteristic triangular gable end. The steepness of the roof was determined by the reduction in size of each gable-wall log as well as the total number of gable-wall logs. Flatter roofed cabins might have had only 2 or 3 gable-wall logs while steeply pitched roofs might have had as many gable-wall logs as a full story. Issues related to eave overhang and a porch also influenced the layout of

3485-449: The classes Bryopsida, Marchantiopsida, and Anthocerotopsida, respectively. The mosses and liverworts are now considered to belong to a clade called Setaphyta . The mosses, (Bryophyta sensu stricto), are divided into eight classes: vascular plants hornworts liverworts Takakiopsida Sphagnopsida Andreaeopsida Andreaeobryopsida Oedipodiopsida Polytrichopsida Tetraphidopsida Bryopsida Six of

Cabin of Peter the Great - Misplaced Pages Continue

3570-539: The crotch. In cool, humid, cloudy climates, all sides of tree trunks and rocks may be equally moist enough for moss growth. Each species of moss requires certain amounts of moisture and sunlight and thus will grow on certain sections of the same tree or rock. Some mosses grow underwater, or completely waterlogged. Many prefer well-drained locations. There are mosses that preferentially grow on rocks and tree trunks of various chemistries. In boreal forests , some species of moss play an important role in providing nitrogen for

3655-596: The decades, increasingly complex joints were developed to ensure more weather tight joints between the logs, but the profiles were still largely based on the round log. A medieval log cabin was considered movable property, evidenced by the relocation of Espåby in 1557, where the buildings were disassembled, transported to a new location, and reassembled. It was also common to replace individual logs damaged by dry rot as necessary. The Wood Museum in Trondheim , Norway, displays fourteen different traditional profiles, but

3740-642: The deep forests of inland Sweden and Norway, during Sweden's 600+ year colonial rule over Finland, who since 1640 were being captured and displaced to the colony. After arriving, they would escape the Fort Christina center where the Swedes lived, to go and live in the forest as they did back home. They encountered the Lenape Indian tribe, with whom they found many cultural similarities, including slash and burn agriculture, sweat lodges and saunas, and

3825-405: The ecosystem due to their relationship with nitrogen-fixing cyanobacteria . Cyanobacteria colonize moss and receive shelter in return for providing fixed nitrogen. Moss releases the fixed nitrogen, along with other nutrients, into the soil "upon disturbances like drying-rewetting and fire events", making it available throughout the ecosystem. Moss is often considered a weed in grass lawns, but

3910-585: The edges of streams, but they can grow anywhere in cool, humid, cloudy climates, and some species are adapted to sunny, seasonally dry areas like alpine rocks or stabilized sand dunes. Choice of substrate varies by species as well. Moss species can be classed as growing on: rocks, exposed mineral soil, disturbed soils, acid soil, calcareous soil, cliff seeps and waterfall spray areas, streamsides, shaded humusy soil, downed logs, burnt stumps, tree trunk bases, upper tree trunks, and tree branches or in bogs . Moss species growing on or under trees are often specific about

3995-613: The eight classes contain only one or two genera each. Polytrichopsida includes 23 genera, and Bryopsida includes the majority of moss diversity with over 95% of moss species belonging to this class. The Sphagnopsida, the peat-mosses, comprise the two living genera Ambuchanania and Sphagnum , as well as fossil taxa. Sphagnum is a diverse, widespread, and economically important one. These large mosses form extensive acidic bogs in peat swamps. The leaves of Sphagnum have large dead cells alternating with living photosynthetic cells. The dead cells help to store water. Aside from this character,

4080-843: The end of the 19th century and beginning of the 20th century. Log cabin building never died out or fell out of favor. It was surpassed by the needs of a growing urban United States. During the 1930s and the Great Depression , the Roosevelt administration directed the Civilian Conservation Corps to build log lodges throughout the west for use by the Forest Service and the National Park Service . Timberline Lodge on Mount Hood in Oregon

4165-420: The exception of the ancient group Takakiopsida , no known mosses form mycorrhiza , but bryophilous fungi is widespread in moss and other bryophytes, where they live as saprotrophs, parasites, pathogens and mutualists, some of them endophytes . Mosses differ from vascular plants in lacking water-bearing xylem tracheids or vessels . As in liverworts and hornworts , the haploid gametophyte generation

4250-669: The exterior and sometimes interior of the house. These cabins are mass manufactured, traditionally in Scandinavian countries and increasingly in Eastern Europe . Squared milled logs are precut for easy assembly. Log homes are popular in rural areas, and even in some suburban locations. In many resort communities in the Western United States , homes of log and stone measuring over 3,000 sq ft (280 m ) are not uncommon. These "kit" log homes are one of

4335-472: The female shoot where their growth is restricted to a few millimeters. In some species, dwarfness is genetically determined, in that all male spores become dwarf. More often, it is environmentally determined in that male spores that land on a female become dwarf, while those that land elsewhere develop into large, female-sized males. In the latter case, dwarf males that are transplanted from females to another substrate develop into large shoots, suggesting that

SECTION 50

#1732780390485

4420-468: The females emit a substance which inhibits the growth of germinating males and possibly also quickens their onset of sexual maturation. The nature of such a substance is unknown, but the phytohormone auxin may be involved Having the males growing as dwarfs on the female is expected to increase the fertilization efficiency by minimizing the distance between male and female reproductive organs. Accordingly, it has been observed that fertilization frequency

4505-443: The fertilization distance. After fertilisation, the immature sporophyte pushes its way out of the archegonial venter. It takes several months for the sporophyte to mature. The sporophyte body comprises a long stalk, called a seta, and a capsule capped by a cap called the operculum . The capsule and operculum are in turn sheathed by a haploid calyptra which is the remains of the archegonial venter. The calyptra usually falls off when

4590-401: The fins on a heat sink. These carry out photosynthesis and may help to conserve moisture by partially enclosing the gas exchange surfaces. The Polytrichopsida differ from other mosses in other details of their development and anatomy too, and can also become larger than most other mosses, with e.g., Polytrichum commune forming cushions up to 40 cm (16 in) high. The tallest land moss,

4675-625: The first log cabins built in North America were in the Swedish colony of New Sweden along the Delaware River and Brandywine River valleys. Most of the settlers were actually Forest Finns , a heavily oppressed Finnish ethnic group originally from Savonia and Tavastia , who starting from the 1500s were displaced or persuaded to go inhabit and practice slash and burn agriculture (which they were famous for in eastern Finland) in

4760-458: The first log structures were probably being built in Northern Europe by the Bronze Age around 3500 BC. C. A. Weslager describes Europeans as having: The Finns were accomplished in building several forms of log housing, having different methods of corner timbering, and they utilized both round and hewn logs. Their log building had undergone an evolutionary process from the crude "pirtti"...

4845-636: The genus Sphagnum ), although they are also used for decorative purposes, such as in gardens and in the florist trade. Traditional uses of mosses included as insulation and for the ability to absorb liquids up to 20 times their weight. Moss is a keystone genus and benefits habitat restoration and reforestation . Botanically, mosses are non-vascular plants in the land plant division Bryophyta. They are usually small (a few centimeters tall) herbaceous (non-woody) plants that absorb water and nutrients mainly through their leaves and harvest carbon dioxide and sunlight to create food by photosynthesis . With

4930-614: The ground by compressed air contained in the capsules; the spores are accelerated to about 36,000 times the earth's gravitational acceleration g . It has recently been found that microarthropods, such as springtails and mites , can effect moss fertilization and that this process is mediated by moss-emitted scents. Male and female fire moss , for example emit different and complex volatile organic scents. Female plants emit more compounds than male plants. Springtails were found to choose female plants preferentially, and one study found that springtails enhance moss fertilization, suggesting

5015-598: The interior. The O'Farrell Cabin ( c.  1865 ) in Boise , Idaho , had backed wallpaper used over newspaper. The C.C.A. Christenson Cabin in Ephraim , Utah ( c.  1880 ) was plastered over willow lath. Log cabins reached their peak of complexity and elaboration with the Adirondack-style cabins of the mid-19th century. This style was the inspiration for many United States Park Service lodges built at

5100-490: The largest consumers of logs in the Western United States. In the United States, log homes have embodied a traditional approach to home building, one that has resonated throughout American history . Log homes represent a technology that allows a home to be built with a high degree of sustainability . They are frequently considered to be on the leading edge of the green building movement. Crib barns were

5185-664: The leaf can be smooth or it may have teeth. There may be a distinct type of cell defining the edge of the leaf, distinct in shape and/or colour from the other leaf cells. Moss has threadlike rhizoids that anchor them to their substrate, comparable to root hairs rather than the more substantial root structures of spermatophytes . Mosses do not absorb water or nutrients from their substrate through their rhizoids. They can be distinguished from liverworts ( Marchantiophyta or Hepaticae) by their multi-cellular rhizoids. Spore-bearing capsules or sporangia of mosses are borne singly on long, unbranched stems, thereby distinguishing them from

SECTION 60

#1732780390485

5270-449: The logs at the ends, resulting in strong structures that were easier to make weather-tight by inserting moss or other soft material into the joints. As the original coniferous forest extended over the coldest parts of the world, there was a prime need to keep these cabins warm. The insulating properties of the solid wood were a great advantage over a timber frame construction covered with animal skins, felt , boards or shingles . Over

5355-426: The orientation of doors and windows all needed to be taken into account when the cabin was designed. In addition, the source of the logs, the source of stone and available labor, either human or animal, had to be considered. If timber sources were further away from the site, the cabin size might be limited. Cabin corners were often set on large stones; if the cabin was large, other stones were used at other points along

5440-400: The outside so that siding might be applied; they also might be hewn inside and covered with a variety of materials, ranging from plaster over lath to wallpaper . Log cabins were constructed with either a purlin roof structure or a rafter roof structure. A purlin roof consists of horizontal logs that are notched into the gable-wall logs. The latter are progressively shortened to form

5525-804: The parent group bryophytes , which comprise liverworts , mosses, and hornworts . Mosses typically form dense green clumps or mats, often in damp or shady locations. The individual plants are usually composed of simple leaves that are generally only one cell thick, attached to a stem that may be branched or unbranched and has only a limited role in conducting water and nutrients. Although some species have conducting tissues, these are generally poorly developed and structurally different from similar tissue found in vascular plants . Mosses do not have seeds and after fertilisation develop sporophytes with unbranched stalks topped with single capsules containing spores . They are typically 0.2–10 cm (0.1–3.9 in) tall, though some species are much larger. Dawsonia ,

5610-426: The pattern in all vascular plants ( seed plants and pteridophytes ), where the diploid sporophyte generation is dominant. Lichens may superficially resemble mosses, and sometimes have common names that include the word "moss" (e.g., " reindeer moss " or " Iceland moss "), but they are fungal symbioses and not related to mosses. The main commercial significance of mosses is as the main constituent of peat (mostly

5695-480: The perichaetum (plural, perichaeta). The archegonia are small flask-shaped clumps of cells with an open neck (venter) down which the male sperm swim. The male organs are known as antheridia ( sing. antheridium ) and are enclosed by modified leaves called the perigonium ( pl. perigonia). The surrounding leaves in some mosses form a splash cup, allowing the sperm contained in the cup to be splashed to neighboring stalks by falling water droplets. Gametophore tip growth

5780-538: The principal sensor of DNA double-strand breaks) showed that these genes are necessary for repair of DNA damage as well as for normal growth and development. More recently, mosses have been grouped with the liverworts and hornworts in the division Bryophyta ( bryophytes , or Bryophyta sensu lato ). The bryophyte division itself contains three (former) divisions: Bryophyta (mosses), Marchantiophyta (liverworts) and Anthocerotophyta (hornworts); it has been proposed that these latter divisions are de-ranked to

5865-464: The production of a diploid sporophyte. The sperm of mosses is biflagellate, i.e. they have two flagellae that aid in propulsion. Since the sperm must swim to the archegonium, fertilisation cannot occur without water. Some species (for example Mnium hornum or several species of Polytrichum ) keep their antheridia in so called 'splash cups', bowl-like structures on the shoot tips that propel the sperm several decimeters when water droplets hit it, increasing

5950-418: The remaining classes, stomata have been lost more than 60 times. Their leaves are simple, usually only a single layer of cells with no internal air spaces, often with thicker midribs (nerves). The nerve can run beyond the edge of the leaf tip, termed excurrent. The tip of the leaf blade can be extended as a hair point, made of colourless cells. These appear white against the dark green of the leaves. The edge of

6035-570: The repair mechanism functions in plants. For example, a study of P. patens mutants defective in Rp RAD51, a gene that encodes a protein at the core of the recombinational repair reaction, indicated that homologous recombination is essential for repairing DNA double-strand breaks in this plant. Similarly, studies of mutants defective in Ppmre11 or Pprad50 (that encode key proteins of the MRN complex ,

6120-568: The repair mechanism known as homologous recombination . If the plant cannot repair DNA damage, e.g., double-strand breaks , in their somatic cells , the cells can lose normal functions or die. If this occurs during meiosis (part of sexual reproduction), they could become infertile. The genome of P. patens has been sequenced, which has allowed several genes involved in DNA repair to be identified. P. patens mutants that are defective in key steps of homologous recombination have been used to work out how

6205-442: The rocks they were growing on. These chemically altered rocks in turn reacted with the atmospheric CO 2 and formed new carbonate rocks in the ocean through the weathering of calcium and magnesium ions from silicate rocks. The weathered rocks also released significant amounts of phosphorus and iron which ended up in the oceans, where it caused massive algal blooms, resulting in organic carbon burial, extracting more carbon dioxide from

6290-499: The rooms came to be known as the "red chambers" ( krasnyie khoromtsy ). There are no fires or chimneys, as it was intended to be used only in the warmer summer months. It was occupied by the Tsar between 1703 and 1708, while Peter supervised the construction of the new imperial city and the Peter and Paul Fortress . Peter had it encased for its protection within a red brick pavilion in 1723, and ordered that it be preserved for posterity as

6375-446: The sill (bottom log). Since they were usually cut into the sill, thresholds were supported with rock as well. These stones are found below the corners of many 18th-century cabins as they are restored. Cabins were set on foundations to keep them out of damp soil but also to allow for storage or basements to be constructed below the cabin. Cabins with earth floors had no need for foundations. In North America , cabins were constructed using

6460-432: The size of the gap between the logs and reduced the amount of chinking (sticks or rocks) or daubing (mud) needed to fill the gap. The length of one log was generally the length of one wall, although this was not a limitation for most good cabin builders. Decisions had to be made about the type of cabin. Styles varied greatly from one part of North America to another: the size of the cabin, the number of stories, type of roof,

6545-473: The species of trees they grow on, such as preferring conifers over broadleaf trees , oaks over alders , or vice versa. While mosses often grow on trees as epiphytes , they are never parasitic on the tree. Mosses are also found in cracks between paving stones in damp city streets, and on roofs. Some species adapted to disturbed, sunny areas are well adapted to urban conditions and are commonly found in cities. Examples would be Rhytidiadelphus squarrosus ,

6630-433: The tallest moss in the world, can grow to 50 cm (20 in) in height. There are approximately 12,000 species. Mosses are commonly confused with liverworts, hornworts and lichens . Although often described as non-vascular plants , many mosses have advanced vascular systems. Like liverworts and hornworts, the haploid gametophyte generation of mosses is the dominant phase of the life cycle . This contrasts with

6715-496: The unique branching, thallose (flat and expanded) protonema, and explosively rupturing sporangium place it apart from other mosses. Andreaeopsida and Andreaeobryopsida are distinguished by the biseriate (two rows of cells) rhizoids, multiseriate (many rows of cells) protonema, and sporangium that splits along longitudinal lines. Most mosses have capsules that open at the top. Polytrichopsida have leaves with sets of parallel lamellae, flaps of chloroplast-containing cells that look like

6800-458: The wild in a water-retaining bag. Some species of moss can be extremely difficult to maintain away from their natural sites with their unique requirements of combinations of light, humidity, substrate chemistry, shelter from wind, etc. Growing moss from spores is even less controlled. Moss spores fall in a constant rain on exposed surfaces; those surfaces which are hospitable to a certain species of moss will typically be colonised by that moss within

6885-513: The year to complete fertilisation. Many mosses can survive desiccation , sometimes for months, returning to life within a few hours of rehydration. It is generally believed that in the Northern Hemisphere , the north side of trees and rocks will generally have more luxuriant moss growth on average than other sides. The reason is assumed to be because sunshine on the south side causes a dry environment. The reverse would be true in

6970-523: Was described by Roman architect Vitruvius Pollio in his architectural treatise De Architectura . He noted that in Pontus in present-day northeastern Turkey , dwellings were constructed by laying logs horizontally overtop of each other and filling in the gaps with "chips and mud". Log cabin construction has its roots in Scandinavia and Eastern Europe . Although their precise origin is uncertain,

7055-459: Was not available, often were covered with long hand-split shingles. The log cabin has been a symbol of humble origins in U.S. politics since the early 19th century. At least seven U.S. presidents were born in log cabins, including Andrew Jackson , James K. Polk , Millard Fillmore , Franklin Pierce , James Buchanan , Abraham Lincoln , and James A. Garfield . Although William Henry Harrison

7140-592: Was not born in a log cabin, he and the Whigs were among the first to use them during the 1840 presidential election as a symbol to show Americans that he was a man of the people. Other candidates followed Harrison's example, making the idea of a log cabin a recurring theme in U.S. presidential campaigns. More than a century after Harrison, Adlai Stevenson II said, "I wasn't born in a log cabin. I didn't work my way through school nor did I rise from rags to riches, and there's no use trying to pretend I did." Stevenson lost

7225-529: Was such a log structure, and it was dedicated by President Franklin D. Roosevelt . In 1930, the world's largest log cabin was constructed at a private resort in Montebello , Quebec , Canada . Often described as a log château, it serves as the Château Montebello hotel. The modern version of a log cabin is the log home , which is a house built usually from milled logs. The logs are visible on

#484515