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Pseudoditrichaceae
''Pseudoditrichum'' is a rare North American genus of haplolepideous moss (Dicranidae). It is the only known genus in its family (Pseudoditrichaceae), and there is only one species in the genus. ''Pseudoditrichum mirabile'' has been found only in a small area along the Sloan River near Great Bear Lake Great Bear Lake ( den, Sahtú; french: Grand lac de l'Ours) is a lake in the boreal forest of Canada. It is the largest lake entirely in Canada (Lake Superior and Lake Huron are larger but straddle the Canada–US border), the fourth-largest .... This is in the Northwest Territory in northern Canada, only a few kilometers south of the Arctic Circle. ''Pseudoditrichum mirabile'' is unusual in that the combination of the gametophyte features and the sporophyte morphology do not match any other moss family. The entire plant is a mere 3 mm tall, growing on moist silt, generally underneath '' Populus''. It spreads vegetatively by means of spherical underground tubers as w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryopsida
The Bryopsida constitute the largest class of mosses, containing 95% of all moss species. It consists of approximately 11,500 species, common throughout the whole world. The group is distinguished by having spore capsules with teeth that are ''arthrodontous''; the teeth are separate from each other and jointed at the base where they attach to the opening of the capsule.Buck, William R. & Bernard Goffinet. (2000) "Morphology and classification of mosses", pages 71-123 ''in'' A. Jonathan Shaw & Bernard Goffinet (Eds.), ''Bryophyte Biology''. (Cambridge: Cambridge University Press). Consequently, mosses in the Class Bryopsida are commonly known as the “joint-toothed” or “arthrodontous” mosses. These teeth are exposed when the covering operculum falls off. In other groups of mosses, the capsule is either ''nematodontous'' with an attached operculum, or else splits open without operculum or teeth. Morphological groups The Bryopsida can be simplified into three groups: the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Campbell Steere
William Campbell Steere (1907–1989) was an American botanist known as an expert on bryophytes, especially arctic and tropical American species. Early life Steere was born November 4, 1907 in Muskegon, Michigan to a family of Irish Quakers. His paternal grandfather was Joseph Beal Steere. Steere attended the University of Michigan, and earned his B.S. in botany with "high distinction". He briefly attended the University of Pennsylvania where he studied cytology under William Randolph Taylor, while also working as an instructor at Temple University. Steere was persuaded by Harley H. Bartlett to return to the University of Michigan as an instructor. He earned his M.A. in 1931 and his Ph.D. from the University in 1932. Career Steere continued to teach botany at the University of Michigan. His research was focused on bryology, and he taught courses in bryology and systematic biology with a focus on Michigan's Upper Peninsula. In 1932, he led a biological survey of the Yucata ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peristome
Peristome (from the Greek ''peri'', meaning 'around' or 'about', and ''stoma'', 'mouth') is an anatomical feature that surrounds an opening to an organ or structure. Some plants, fungi, and shelled gastropods have peristomes. In mosses In mosses, the peristome is a specialized structure in the sporangium that allows for gradual spore discharge, instead of releasing them all at once. Most mosses produce a capsule with a lid (the operculum) which falls off when the spores inside are mature and thus ready to be dispersed. The opening thus revealed is called the ''stoma'' (meaning "mouth") and is surrounded by one or two peristomes. Each peristome is a ring of triangular "teeth" formed from the remnants of dead cells with thickened cell walls. There are usually 16 such teeth in a single peristome, separate from each other and able to both fold in to cover the stoma as well as fold back to open the stoma. This articulation of the teeth is termed arthrodontous and is found in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moss
Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to 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 tall, though some species are much larger. ''Dawsonia'', the tallest moss in the world, can grow to in height. There are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicranidae
The Dicranidae are a widespread and diverse subclass of mosses in class Bryopsida, with many species of dry or disturbed areas. They are distinguished by their spores; the peristome Peristome (from the Greek ''peri'', meaning 'around' or 'about', and ''stoma'', 'mouth') is an anatomical feature that surrounds an opening to an organ or structure. Some plants, fungi, and shelled gastropods have peristomes. In mosses In mosses, ... teeth are haplolepideous with a 4:2:3 formula, and an exostome is absent. References Plant subclasses Bryopsida {{Bryophyte-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Bear Lake
Great Bear Lake ( den, Sahtú; french: Grand lac de l'Ours) is a lake in the boreal forest of Canada. It is the largest lake entirely in Canada (Lake Superior and Lake Huron are larger but straddle the Canada–US border), the fourth-largest in North America, and the eighth-largest in the world. The lake is in the Northwest Territories, on the Arctic Circle between 65 and 67 degrees of northern latitude and between 118 and 123 degrees western longitude, above sea level. The name originated from the Chipewyan language word , meaning "grizzly bear water people". The Sahtu, a Dene people, are named after the lake. Grizzly Bear Mountain on the shore of the lake also comes from Chipewyan, meaning, "bear large hill".Johnson, LThe Great Bear Lake: Its Place in History Calgary, Alberta: ''Arctic Institute of North America'' (AINA) database at the University of Calgary. pp. 236-237. Retrieved on: 2012-01-30. The Sahoyue (Grizzly Bear Mountain) peninsula on the south side of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northwest Territory
The Northwest Territory, also known as the Old Northwest and formally known as the Territory Northwest of the River Ohio, was formed from unorganized western territory of the United States after the American Revolutionary War. Established in 1787 by the Congress of the Confederation through the Northwest Ordinance, it was the nation's first post-colonial organized incorporated territory. At the time of its creation, the territory included all the land west of Pennsylvania, northwest of the Ohio River and east of the Mississippi River below the Great Lakes, and what later became known as the Boundary Waters. The region was ceded to the United States in the Treaty of Paris of 1783. Throughout the Revolutionary War, the region was part of the British Province of Quebec. It spanned all or large parts of six eventual U.S. states (Ohio, Indiana, Illinois, Michigan, Wisconsin, and the northeastern part of Minnesota). Reduced to present-day Ohio, eastern Michigan and a sliver of sout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Circle
The Arctic Circle is one of the two polar circles, and the most northerly of the five major circles of latitude as shown on maps of Earth. Its southern equivalent is the Antarctic Circle. The Arctic Circle marks the southernmost latitude at which, on the December solstice, the shortest day of the year in the northern hemisphere, the sun will not rise all day, and on the June solstice, the longest day of the year in the northern hemisphere, the sun will not set. These phenomena are referred to as polar night and midnight sun respectively, and the further north one progresses, the more pronounced these effects become. For example, in the Russian port city of Murmansk, three degrees above the Arctic Circle, the sun does not rise for 40 successive days in midwinter. The position of the Arctic Circle is not fixed and currently runs north of the Equator. Its latitude depends on the Earth's axial tilt, which fluctuates within a margin of more than 2° over a 41,000-year period, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Populus
''Populus'' is a genus of 25–30 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar (), aspen, and cottonwood. The western balsam poplar ('' P. trichocarpa'') was the first tree to have its full DNA code determined by DNA sequencing, in 2006. Description The genus has a large genetic diversity, and can grow from tall, with trunks up to in diameter. The bark on young trees is smooth, white to greenish or dark gray, and often has conspicuous lenticels; on old trees, it remains smooth in some species, but becomes rough and deeply fissured in others. The shoots are stout, with (unlike in the related willows) the terminal bud present. The leaves are spirally arranged, and vary in shape from triangular to circular or (rarely) lobed, and with a long petiole; in species in the sections ''Populus'' and ''Aigeiros'', the petioles are laterally flattened, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemma (botany)
A gemma (plural ''gemmae'') is a single cell, or a mass of cells, or a modified bud of tissue, that detaches from the parent and develops into a new individual. This type of asexual reproduction is referred to as fragmentation. It is a means of asexual propagation in plants. These structures are commonly found in fungi, algae, liverworts and mosses, but also in some flowering plants such as pygmy sundews and some species of butterworts. Vascular plants have many other methods of asexual reproduction including bulbils and turions. In mosses and liverworts The production of gemmae is a widespread means of asexual reproduction in both liverworts and mosses. In liverworts such as ''Marchantia'', the flattened plant body or thallus is a haploid gametophyte A gametophyte () is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryophyta Of North America )
{{Disambiguation ...
Bryophyta may refer to: * Mosses – Bryophyta in the strict sense; a specific group of leafy nonvascular plants, now regarded as Division Bryophyta * Bryophytes – Bryophyta in the broad sense; a group of plants regarded as a single division by some, but further split into: ** mosses (Bryophyta) ** hornworts (Anthocerotophyta) **liverworts (Marchantiophyta The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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