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Horsetails
''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a " living fossil", the only living genus of the entire subclass Equisetidae, which for over 100 million years was much more diverse and dominated the understorey of late Paleozoic forests. Some equisetids were large trees reaching to tall. The genus '' Calamites'' of the family Calamitaceae, for example, is abundant in coal deposits from the Carboniferous period. The pattern of spacing of nodes in horsetails, wherein those toward the apex of the shoot are increasingly close together, is said to have inspired John Napier to invent logarithms. Modern horsetails first appeared during the Jurassic period. A superficially similar but entirely unrelated flowering plant genus, mare's tail ('' Hippuris''), is occasionally referred to as "horsetail", and adding to confusion, the name "mare's tail" is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equisetidae
Equisetidae is one of the four subclasses of Polypodiopsida (ferns), a group of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. They typically grow in wet areas, with whorls of needle-like branches radiating at regular intervals from a single vertical stem. The Equisetidae were formerly regarded as a separate division of spore plants and called Equisetophyta, Arthrophyta, Calamophyta or Sphenophyta. When treated as a class, the names Equisetopsida s.s. and Sphenopsida have also been used. They are now recognized as rather close relatives of the ferns (Polypodiopsida) of which they form a specialized lineage. However, the division between the horsetails and the other ferns is so ancient that many botanists, especially paleobotanists, still regard this group as fundamentally separate at the higher level. Description The horsetails comprise photosynthesising, "segmented", hollow stems, sometimes filled with pith. At the j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equisetaceae
Equisetaceae, sometimes called the horsetail family, is the only extant family of the order Equisetales, with one surviving genus, ''Equisetum'', which comprises about twenty species. Evolution and systematics Equisetaceae is the only surviving family of the Equisetales, a group with many fossils of large tree-like plants that possessed ribbed stems similar to modern horsetails. ''Pseudobornia'' is the oldest known relative of ''Equisetum''; it grew in the late Devonian, about 375 million years ago and is assigned to its own order. All living horsetails are placed in the genus ''Equisetum''. But there are some fossil species that are not assignable to the modern genus. ''Equisetites'' is a " wastebin taxon" uniting all sorts of large horsetails from the Mesozoic; it is almost certainly paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is sai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calamites
''Calamites'' is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus ''Equisetum'') are closely related. Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights of 30-50 meters (100-160 feet). They were components of the understories of coal swamps of the Carboniferous Period (around ). Taxonomy A number of organ taxa have been identified as part of a united organism, which has inherited the name ''Calamites'' in popular culture. ''Calamites'' correctly refers only to casts of the stem of Carboniferous/Permian sphenophytes, and as such is a form genus of little taxonomic value. There are two forms of casts, which can give mistaken impressions of the organisms. The most common is an internal cast of the hollow (or pith-filled) void in the centre of the trunk. This can cause some confusion: firstly, it must be remembered that a fossil was probably surrounded with 4-5 times its width in (unpres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fern
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calamitaceae
Calamitaceae is an extinct family of plants related to the modern horsetails. Some members of this family attained tree-like stature during the Carboniferous Period (around ) and in Permian Period, reaching heights of up to 20 meters. The family takes its name from its principal genus ''Calamites''. Because some proposed species are based on partial fossil records, it is not clear if these are merely different parts of the same type. Proposed genera and species of Calamitaceae * ''Annularia''. ** ''A. stellata''. * '' Arthropitys''. * '' Asterophyllites'' (or incorrectly ''Asterophyllum''). * '' Astromyelon''. * ''Calamites ''Calamites'' is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus '' Equisetum'') are closely related. Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights o ...''. ** ''C. carinatus''. ** ''C. suckowi''. ** ''C. undulatus''. * '' Calamocarpon''. * '' Calamostachy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equisetum Arvense
''Equisetum arvense'', the field horsetail or common horsetail, is an herbaceous perennial plant in the Equisetidae (horsetails) sub-class, native throughout the arctic and temperate regions of the Northern Hemisphere. It has separate sterile non-reproductive and fertile spore-bearing stems growing from a perennial underground rhizomatous stem system. The fertile stems are produced in early spring and are non- photosynthetic, while the green sterile stems start to grow after the fertile stems have wilted and persist through the summer until the first autumn frosts.Hyde, H. A., Wade, A. E., & Harrison, S. G. (1978). ''Welsh Ferns''. National Museum of Wales .Flora of North America''Equisetum arvense''/ref> It is sometimes confused with mare's tail, '' Hippuris vulgaris''. Rhizomes can pierce through the soil up to in depth. This allows this species to tolerate many conditions and is hard to get rid of even with the help of herbicides. Taxonomy Linnaeus described field horset ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The New Yorker
''The New Yorker'' is an American weekly magazine featuring journalism, commentary, criticism, essays, fiction, satire, cartoons, and poetry. Founded as a weekly in 1925, the magazine is published 47 times annually, with five of these issues covering two-week spans. Although its reviews and events listings often focus on the cultural life of New York City, ''The New Yorker'' has a wide audience outside New York and is read internationally. It is well known for its illustrated and often topical covers, its commentaries on popular culture and eccentric American culture, its attention to modern fiction by the inclusion of short stories and literary reviews, its rigorous fact checking and copy editing, its journalism on politics and social issues, and its single-panel cartoons sprinkled throughout each issue. Overview and history ''The New Yorker'' was founded by Harold Ross and his wife Jane Grant, a ''New York Times'' reporter, and debuted on February 21, 1925. Ross wanted t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flowering Plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants that produce their seeds enclosed within a fruit. They are by far the most diverse group of land plants with 64 orders, 416 families, approximately 13,000 known genera and 300,000 known species. Angiosperms were formerly called Magnoliophyta (). Like gymnosperms, angiosperms are seed-producing plants. They are distinguished from gymnosperms by characteristics including flowers, endosperm within their seeds, and the production of fruits that contain the seeds. The ancestors of flowering plants diverged from the common ancestor of all living gymnosperms before the end of the Carboniferous, over 300 million years ago. The closest fossil relatives of flowering plants are uncertain and contentious. The earliest angiosperm fossils ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hippuris
''Hippuris'', the mare's tail, was previously the sole genus in the family Hippuridaceae. Following genetic research by the Angiosperm Phylogeny Group, it has now been transferred to the family Plantaginaceae, with Hippuridaceae being reduced to a synonym of Plantaginaceae. It includes one to three species depending on taxonomic interpretation. Some authorities only accept the first species of those listed below, treating the other two as synonyms of it: * Common mare's tail, '' Hippuris vulgaris'' ** Mountain mare's tail, '' Hippuris montana'' ** Fourleaf mare's tail, '' Hippuris tetraphylla'' They are aquatic plants found in shallow ponds and streams, both slow-moving and fast-flowing. This flowering plant is sometimes mistakenly identified as the non-flowering horsetail ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evidence-based Medicine
Evidence-based medicine (EBM) is "the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients". The aim of EBM is to integrate the experience of the clinician, the values of the patient, and the best available scientific information to guide decision-making about clinical management. The term was originally used to describe an approach to teaching the practice of medicine and improving decisions by individual physicians about individual patients. Background, history and definition Medicine has a long history of scientific inquiry about the prevention, diagnosis, and treatment of human disease. The concept of a controlled clinical trial was first described in 1662 by Jan Baptist van Helmont in reference to the practice of bloodletting. Wrote Van Helmont: The first published report describing the conduct and results of a controlled clinical trial was by James Lind, a Scottish naval surgeon who conducted re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traditional Medicine
Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the era of modern medicine. The World Health Organization (WHO) defines traditional medicine as "the sum total of the knowledge, skills, and practices based on the theories, beliefs, and experiences indigenous to different cultures, whether explicable or not, used in the maintenance of health as well as in the prevention, diagnosis, improvement or treatment of physical and mental illness". Traditional medicine is often contrasted with scientific medicine. In some Asian and African countries, up to 80% of the population relies on traditional medicine for their primary health care needs. When adopted outside its traditional culture, traditional medicine is often considered a form of alternative medicine. Practices known as traditional medici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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