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Physematium Obtusum
''Physematium obtusum'', the bluntlobe cliff fern, is a common rock fern of Appalachia and eastern North America. It prefers a calcareous substrate, but also grows in neutral soils. It may grow on rock faces or in scree. This fern is often confused with various ferns of the genus ''Cystopteris ''Cystopteris'' is a genus of ferns in the family Cystopteridaceae. These are known generally as bladderferns or fragile ferns. They grow in temperate areas worldwide. This is a very diverse genus and within a species individuals can look quite ...'' but is distinguished by its hairy nature. References obtusum Ferns of Canada Ferns of the United States Plants described in 1840 {{Polypodiales-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torr
The torr (symbol: Torr) is a unit of pressure based on an absolute scale, defined as exactly of a standard atmosphere (). Thus one torr is exactly (≈ ). Historically, one torr was intended to be the same as one "millimeter of mercury", but subsequent redefinitions of the two units made them slightly different (by less than ). The torr is not part of the International System of Units (SI). It is often combined with the metric prefix milli to name one millitorr (mTorr) or 0.001 Torr. The unit was named after Evangelista Torricelli, an Italian physicist and mathematician who discovered the principle of the barometer in 1644. Nomenclature and common errors The unit name ''torr'' is written in lower case, while its symbol ("Torr") is always written with upper-case initial; including in combinations with prefixes and other unit symbols, as in "mTorr" (millitorr) or "Torr⋅L/s" (torr-litres per second). The symbol (uppercase) should be used with prefix symbols (thus, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appalachia
Appalachia () is a cultural region in the Eastern United States that stretches from the Southern Tier of New York State to northern Alabama and Georgia. While the Appalachian Mountains stretch from Belle Isle in Newfoundland and Labrador, Canada, to Cheaha Mountain in Alabama, ''Appalachia'' typically refers only to the cultural region of the central and southern portions of the range, from the Catskill Mountains of New York southwest to the Blue Ridge Mountains which run southwest from southern Pennsylvania to northern Georgia, and the Great Smoky Mountains of Tennessee and North Carolina. In 2020, the region was home to an estimated 26.1 million people, of which roughly 80% are white. Since its recognition as a distinctive region in the late 19th century, Appalachia has been a source of enduring myths and distortions regarding the isolation, temperament, and behavior of its inhabitants. Early 20th century writers often engaged in yellow journalism focused on sensational ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Plate, North American Tectonic Plate, Greenland is included as a part of North America geographically. North America covers an area of about , about 16.5% of Earth's land area and about 4.8% of its total surface. North America is the third-largest continent by area, following Asia and Africa, and the list of continents and continental subregions by population, fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in List of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's population. In Americas (terminology)#Human ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cystopteris
''Cystopteris'' is a genus of ferns in the family Cystopteridaceae. These are known generally as bladderferns or fragile ferns. They grow in temperate areas worldwide. This is a very diverse genus and within a species individuals can look quite different, especially in harsh environments where stress stunts their growth. They hybridize easily with each other and identifying an individual can be challenging. In general these are rhizomatous perennials which grow in rocks or soil. Their leaves are multiply pinnate, in that each leaflet is divided into smaller parts. The sori are usually rounded and covered in an inflated bladder-like indusium. Species Species include: *'' Cystopteris alpina'' *'' Cystopteris bulbifera'' - bulblet fern *''Cystopteris chinensis'' (Ching) R.Wei & X.C.Zhang (syn. ''Cystoathyrium chinense'' Ching) *''Cystopteris diaphana'' *'' Cystopteris dickieana'' - Dickie's bladderfern *'' Cystopteris douglasii'' - Douglas' bladderfern *'' Cystopteris fragilis'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physematium
''Physematium'' is a genus of ferns in the family Woodsiaceae. It was treated as a synonym of '' Woodsia'' until 2020 when a molecular phylogenetic study showed its distinctiveness. , Plants of the World Online continued to treat the genus as a synonym of ''Woodsia''. Species , World Ferns accepted 20 species and two hybrids: *''Physematium fragile'' (Trevis.) Kunze *'' Physematium indusiosum'' (Christ) Li Bing Zhang, N.T.Lu & X.F.Gao *''Physematium kangdingense'' (H.S.Kung, Li Bing Zhang & X.S.Guo) Li Bing Zhang, N.T.Lu & X.F.Gao * ''Physematium'' × ''kansanum'' (R.E.Brooks) Li Bing Zhang, N.T.Lu & X.F.Gao *''Physematium manchuriense'' (Hook.) Nakai * ''Physematium'' × ''maxonii'' (R.M.Tryon) Li Bing Zhang, N.T.Lu & X.F.Gao *''Physematium mexicanum'' (Fée) comb.ined. *''Physematium molle'' Kaulf. *''Physematium montevidense'' (Spreng.) Shmakov *''Physematium neomexicanum'' (Windham) Li Bing Zhang, N.T.Lu & X.F.Gao *'' Physematium obtusum'' (Spreng.) Hook. *''Physematium orega ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferns Of Canada
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except the lycopods, and differ from mosses and other bryophytes by being vascular, i.e., having specialized tissues that conduct water and nutrients and in having life cycles in which the branched sporophyte is the dominant phase. Ferns have complex leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled fiddleheads that uncoil and expand into fronds. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the Polypodiopsida, comprising both the leptosporangiate ( Polypodiidae) and eusporangiate ferns, the latter group including horsetails, whisk ferns, marattioid ferns, and ophioglossoid f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferns Of The United States
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except the lycopods, and differ from mosses and other bryophytes by being vascular, i.e., having specialized tissues that conduct water and nutrients and in having life cycles in which the branched sporophyte is the dominant phase. Ferns have complex leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled fiddleheads that uncoil and expand into fronds. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the Polypodiopsida, comprising both the leptosporangiate ( Polypodiidae) and eusporangiate ferns, the latter group including horsetails, whisk ferns, marattioid ferns, and ophioglossoid f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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