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Senecio Inaequidens
''Senecio inaequidens'', known as narrow-leaved ragwort and South African ragwort, is a species of flowering plant in the daisy family Asteraceae. Description ''Senecio inaequidens'' is a perennial chamaephyte up to 1 m in height, often much ramified, with each stem ending in one or a few capitula yellow in colour, forming a loose floral display. A single plant produces 26 to 500 capitula each year, with approximately 90 florets, 74% of them developing a viable achene. The leaves are linear, entire or almost so and without petioles. ''S. inaequidens'' exists as a diploid genotype and a tetraploid cytotype. Initially the diploid ''S. madagascarensis'' and ''S. harveianus'' were assumed to be different species; however molecular analysis showed that they only differ in cytotype. Distribution It is native to Southern Africa, including Lesotho, South Africa, Eswatini, Namibia, Mozambique and Botswana. Habitat In its native habitat ''S. inaequidens'' occurs at elevations from s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural History Museum Of Geneva
The Natural History Museum of Geneva (in French: ') is a natural history museum in Geneva, Switzerland. Louis Jurine’s collections of Hymenoptera, Coleoptera, Lepidoptera and Hemiptera are held by the museum. Other displays include a collection of intricate glass models of invertebrates by Leopold and Rudolf Blaschka and a living specimen of a two headed tortoise named Janus. The tortoise is considered the mascot of the museum and is one of their main attractions. Notable people who worked for the museum *Aloïs Humbert, naturalist and paleontologist, curator since 1852 *Auguste Louis Brot, malacologist, curator and researcher (1855-1896) * Emil Frey-Gessner, entomologist, conservator of the entomological collections from 1872 *Émile Dottrens, scientific assistant for zoology *François Jules Pictet de la Rive, curator of paleontological collections *Henri Louis Frédéric de Saussure, member of the managing committee *Jules Favre, curator (1915-1952) * Perceval de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytotype
A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by determining the chromosome complement of an individual, including the number of chromosomes and any abnormalities. A karyogram or idiogram is a graphical depiction of a karyotype, wherein chromosomes are organized in pairs, ordered by size and position of centromere for chromosomes of the same size. Karyotyping generally combines light microscopy and photography, and results in a photomicrographic (or simply micrographic) karyogram. In contrast, a schematic karyogram is a designed graphic representation of a karyotype. In schematic karyograms, just one of the sister chromatids of each chromosome is generally shown for brevity, and in reality they are generally so close together that they look as one on photomicrographs as well u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Senecio
''Senecio'' is a genus of flowering plants in the daisy family (Asteraceae) that includes ragworts and groundsels. Variously circumscribed taxonomically, the genus ''Senecio'' is one of the largest genera of flowering plants. Description Morphology The flower heads are normally rayed with the heads borne in branched clusters, and usually completely yellow, but green, purple, white and blue flowers are known as well. In its current circumscription, the genus contains species that are annual or perennial herbs, shrubs, small trees, aquatics or climbers. The only species which are trees are the species formerly belonging to '' Robinsonia'' occurring on the Juan Fernández Islands. Chemistry Pyrrolizidine alkaloids are found in all ''Senecio'' species. These alkaloids serve as a natural biocides to deter or even kill animals that would eat them. Livestock generally do not find them palatable. ''Senecio'' species are used as food plants by the larvae of some Lepidoptera species t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrrolizidine Alkaloids
Pyrrolizidine alkaloids (PAs), sometimes referred to as necine bases, are a group of naturally occurring alkaloids based on the structure of pyrrolizidine. Pyrrolizidine alkaloids are produced by plants as a defense mechanism against insect herbivores. More than 660 PAs and PA N-oxides have been identified in over 6,000 plants, and about half of them exhibit hepatotoxicity. They are found frequently in plants in the Boraginaceae, Asteraceae, Orchidaceae and Fabaceae families; less frequently in the Convolvulaceae and Poaceae, and in at least one species in the Lamiaceae. It has been estimated that 3% of the world’s flowering plants contain pyrrolizidine alkaloids. Honey can contain pyrrolizidine alkaloids, as can grains, milk, offal and eggs. To date (2011), there is no international regulation of PAs in food, unlike those for herbs and medicines. Unsaturated pyrrolizidine alkaloids are hepatotoxic, that is, damaging to the liver. PAs also cause hepatic veno-occlusive disea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Senecio Madagascariensis
''Senecio madagascariensis'', also known as Madagascar ragwort, is a species of the genus ''Senecio'' and family Asteraceae that is native to Southern Africa. Other common names include Madagascar groundsel and fireweed. It has been included on the noxious weeds list for Hawaii and the reject list for Australia. ''S.madagascariensis'' is the diploid cytotype of S.inaequidens. Description It is an erect, glabrous (smooth stemmed) herb that grows up to 20–60 cm in length. It may become woody and shrub-like in appropriate conditions. Leaves are alternate, narrow-lanceolate to elliptic in shape, usually bright green, smooth with margins that are lobed, serrate or entire. The broader, larger leaves are stem clenching and fleshy, 2–7 cm long and 3-10mm wide. The flowerhead, which is part of an unfirm corymb, is made up of disc florets and ray florets, and is small, yellow and daisy-like, from 1–2 cm in diameter. The plant flowers between late autumn and early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of Norway. Bouvet Island, located in the Subantarctic, is a dependency of Norway; it also lays claims to the Antarctic territories of Peter I Island and Queen Maud Land. The capital and largest city in Norway is Oslo. Norway has a total area of and had a population of 5,425,270 in January 2022. The country shares a long eastern border with Sweden at a length of . It is bordered by Finland and Russia to the northeast and the Skagerrak strait to the south, on the other side of which are Denmark and the United Kingdom. Norway has an extensive coastline, facing the North Atlantic Ocean and the Barents Sea. The maritime influence dominates Norway's climate, with mild lowland temperatures on the se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpine Transhumance
Alpine transhumance is transhumance as practiced in the Alps, that is, a seasonal droving of grazing livestock between the valleys in winter and the high mountain pastures in summer (German language, German ' from the term for "seasonal mountain pasture", '). Transhumance is a traditional practice that has shaped much of the landscape in the Alps, as without it, most areas below would be forests. While tourism and industry contribute today much to Alpine economy, seasonal migration to high pastures is still practiced in Bavaria, Austria, Slovenia, Italy, France and Switzerland, except in their most frequented tourist centers. In some places, cattle are taken care of by local farmer families who move to higher places. In others, this job is for herdsmen who are employees of the cooperative owning the pastures. Most Alpine pastures are below ; all are below . The higher regions not suitable for transhumance are known as the High Alps. Etymology The German word ''Alp'' or ''Alm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecological Succession
Ecological succession is the process of change in the species that make up an ecological community over time. The process of succession occurs either after the initial colonization of a newly created habitat, or after a disturbance substantially alters a pre-existing habitat. Succession that begins in new habitats, uninfluenced by pre-existing communities, is called primary succession, whereas succession that follows disruption of a pre-existing community is called secondary succession. Primary succession may happen after a lava flow or the emergence of a new island from the ocean. Surtsey, a volcanic island off the southern coast of Iceland, is an important example of a place where primary succession has been observed. On the other hand, secondary succession happens after disturbance of a community, such as from a fire, severe windthrow, or logging. Succession was among the first theories advanced in ecology. Ecological succession was first documented in the Indiana Du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pioneer Species
Pioneer species are hardy species that are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by wildfire. Pioneer flora Some lichens grow on rocks without soil, so may be among the first of life forms, and break down the rocks into soil for plants.LICHEN BIOLOGY AND THE ENVIRONMENT, LICHENS OF NORTH AMERICA, Sylvia and Stephen Sharnoff/ref> Since some uninhabited land may have thin, poor quality soils with few nutrients, pioneer species are often hardy plants with adaptations such as long roots, root nodes containing Diazotroph, nitrogen-fixing bacteria, and leaves that employ transpiration. Note that they are often photosynthetic plants, as no other source of energy (such as other species) except light energy is often available in the early stages of succession, thus making it less likely for a pioneer species to be non-photosynthetic. The plants that are often pioneer species also tend to be wind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invasive Species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native species that become harmful to their native environment after human alterations to its food webfor example the purple sea urchin (''Strongylocentrotus purpuratus'') which has decimated kelp forests along the northern California coast due to overharvesting of its natural predator, the California sea otter (''Enhydra lutris''). Since the 20th century, invasive species have become a serious economic, social, and environmental threat. Invasion of long-established ecosystems by organisms is a natural phenomenon, but human-facilitated introductions have greatly increased the rate, scale, and geographic range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia and it is located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. Comprising the westernmost peninsulas of Eurasia, it shares the continental landmass of Afro-Eurasia with both Africa and Asia. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south and Asia to the east. Europe is commonly considered to be Boundaries between the continents of Earth#Asia and Europe, separated from Asia by the drainage divide, watershed of the Ural Mountains, the Ural (river), Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea and the waterways of the Turkish Straits. "Europe" (pp. 68–69); "Asia" (pp. 90–91): "A commonly accepted division between Asia and E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neophyte (botany)
In botany, a neophyte (from Greek νέος (''néos'') "new" and φυτόν (''phutón'') "plant") is a plant species which is not native to a geographical region and was introduced in recent history. Non-native plants that are long-established in an area are called archaeophytes. In Britain, neophytes are defined more specifically as plant species that were introduced after 1492, when Christopher Columbus arrived in the New World and the Columbian Exchange began. Terminology The terminology of the invasion biology is very uneven. In the English-speaking world, terms such as invasive species or the like are mainly used, which is interpreted differently and do not differentiate between different groups of animals or characteristics of the species. The International Union for Conservation of Nature and Natural Resources (IUCN) differentiates in its definitions between alien species and invasive alien species; Alien species are species that have been introduced into a foreign area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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