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Scalesia Stewartii
''Scalesia'' is a genus in the family Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae ... endemic (ecology), endemic to the Galapagos Islands. It contains fifteen species that grow as shrubs or trees. This is unusual, because tree species are uncommon in Asteraceae. The genus ''Scalesia'' resulted from a blunder by George Arnott Walker-Arnott, Arnott who named it in honour of "W. Scales Esq., Cawdor Castle, Elginshire" but discovered after publication that the name should have read 'Stables', after Scottish botanist, William Alexander Stables (1810–1890). All of the species have soft, pithy wood. ''Scalesia'' species have been called "the Darwin's finches of the plant world" because they show a similarly dramatic pattern of adaptive radiation. One of the largest and mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Arnott Walker-Arnott
George Arnott Walker Arnott of Arlary (6 February 1799 – 17 April 1868) was a Scottish botanist. Early life George Arnott Walker Arnott was born in Edinburgh in 1799, the son of David Walker Arnott of Arlary. He attended Milnathort Parish School then the High School of Edinburgh. He studied law in Edinburgh. Career Walker Arnott became a botanist, holding the position of Regius Professor of Botany in the University of Glasgow from 1845 to 1868. He studied the botany of North America with Sir William Hooker and collaborated with Robert Wight in studies of Indian botany. He and William J. Hooker went through the Australian collected plant material of Alexander Collie, which was sent back to the UK after his death.Ray Desmond (Editor) He was a member of the Societe de Histoire Naturelle in Paris and the Moscow Imperial Society of Natural History. Personal life and death Walker Arnott married Mary Hay Barclay in 1831. He died in Glasgow in 1868, aged 69, and is bur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalesia Villosa
''Scalesia villosa'' is a species of flowering plant in the family Asteraceae. It is found only in Ecuador. It is threatened by habitat loss. References villosa ''Villosa'' is a genus of freshwater mussels, aquatic bivalve molluscs in the family Unionidae. Species Species within the genus ''Villosa'': * '' Villosa amygdala'' * ''Villosa arkansasensis'' - Ouachita creekshell * ''Villosa choctawensis ... Flora of Ecuador Vulnerable plants Taxonomy articles created by Polbot {{Heliantheae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalesia
''Scalesia'' is a genus in the family Asteraceae endemic to the Galapagos Islands. It contains fifteen species that grow as shrubs or trees. This is unusual, because tree species are uncommon in Asteraceae. The genus ''Scalesia'' resulted from a blunder by Arnott who named it in honour of "W. Scales Esq., Cawdor Castle, Elginshire" but discovered after publication that the name should have read 'Stables', after Scottish botanist, William Alexander Stables (1810–1890). All of the species have soft, pithy wood. ''Scalesia'' species have been called "the Darwin's finches of the plant world" because they show a similarly dramatic pattern of adaptive radiation. One of the largest and most widespread species is '' Scalesia pedunculata'' – a large tree which grows up to 15 to 20 metres tall, reaching maturity in a few years time. These trees typically grow in dense stands of the same species and age. They die around the same time, and then a new generation of seedlings grows up in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floreana Island
Floreana Island (Spanish: ''Isla Floreana'') is an island of the Galápagos Islands. It was named after Juan José Flores, the first president of Ecuador, during whose administration the government of Ecuador took possession of the archipelago. It was previously called Charles Island (after King Charles II of England), and Santa María after one of the caravels of Columbus. The island has an area of . It was formed by volcanic eruption. The island's highest point is Cerro Pajas at , which is also the highest point of the volcano like most of the smaller islands of Galápagos. History Since the 19th century, whalers kept a wooden barrel at Post Office Bay, so that mail could be picked up and delivered to their destination by ships on their way home, mainly to Europe and the United States. Cards and letters are still placed in the barrel without any postage. Visitors sift through the letters and cards in order to deliver them by hand. Due to its relatively flat surface, su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santiago Island (Galápagos)
Santiago Island () is one of the Galápagos Islands. It is also known as San Salvador, named after the first island discovered by Columbus in the Caribbean Sea (see San Salvador Island), or as James Island. The island, which consists of two overlapping volcanoes, has an area of and a maximum altitude of , atop the northwestern shield volcano. The volcano in the island's southeast erupted along a linear fissure, and is much lower. The oldest lava flows on the island date back to 750,000 years ago. Geology Santiago Island was formed from a shield volcano eponymously named Santiago. The low, flat summits of the volcano allowed the low-viscosity lava to flow for large distances from the source vents. The volcanic origin of the island has led it to be dotted with holocene pyroclastic rock that can be found across the island. On the eastern and western sides of the island, tuff cones, formed from the rapid interaction of hot lava and water, are visible. The summit of the vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Cristóbal Island
San Cristóbal Island ( es, Isla San Cristóbal) and named previously by the English as ''Chatham Island'', is the easternmost island in the Galápagos archipelago, as well as one of the oldest geologically. It is administratively part of San Cristóbal Canton, Ecuador. Its Spanish (and official Ecuadorian) name "San Cristóbal" comes from the patron saint of seafarers, St. Christopher. English speakers increasingly use that name in preference to the traditional English name of Chatham Island, derived from William Pitt, 1st Earl of Chatham. History San Cristobal Island is composed of three or four fused volcanoes, all extinct. It is home to the oldest permanent settlement of the islands and is the island where Darwin first went ashore in 1835. A small lake called El Junco is the only source of fresh water in the islands. The availability of fresh water is what led to the early settlement of San Cristobal. A penal colony was built on San Cristóbal Island in 1880 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Cruz Island (Galápagos)
Santa Cruz Island () is one of the Galápagos Islands with an area of and a maximum altitude of . Situated in the center of the archipelago, Santa Cruz is the second largest island after Isabela. Its capital is Puerto Ayora, the most populated urban centre in the islands. On Santa Cruz, there are some small villages, whose inhabitants work in agriculture and cattle raising. The island is an oval-shaped, long and wide shield volcano. Its summit contains a shallow caldera that has been largely buried by youthful pit craters and cinder cones with well-preserved craters. The most recent eruptions may have occurred only a few thousand years ago with the effusion of sparsely vegetated lava flows from vents on the north flank and along the summit fissure. A gigantic lava tube measuring over long is a tourist attraction on the island. As a testimony to its volcanic history there are two big holes formed by the collapse of a magma chamber: Los Gemelos, or "The Twins". Named aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptive Radiation
In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic interactions or opens new environmental niches. Starting with a single ancestor, this process results in the speciation and phenotypic adaptation of an array of species exhibiting different morphological and physiological traits. The prototypical example of adaptive radiation is finch speciation on the Galapagos ("Darwin's finches"), but examples are known from around the world. Characteristics Four features can be used to identify an adaptive radiation: #A common ancestry of component species: specifically a ''recent'' ancestry. Note that this is not the same as a monophyly in which ''all'' descendants of a common ancestor are included. #A phenotype-environment correlation: a ''significant'' association between environments and the mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darwin's Finches
Darwin's finches (also known as the Galápagos finches) are a group of about 18 species of passerine birds. They are well known for their remarkable diversity in beak form and function. They are often classified as the subfamily Geospizinae or tribe (biology), tribe Geospizini. They belong to the Thraupidae, tanager Family (biology), family and are not closely related to the true finches. The closest known relative of the Galápagos finches is the South American ''Dull-coloured grassquit, Tiaris obscurus''. They were first collected when Second voyage of HMS Beagle, the second voyage of the ''Beagle'' visited the Galápagos Islands, with Charles Darwin on board as a gentleman naturalist. Apart from the Cocos finch, which is from Cocos Island, the others are found only on the Galápagos Islands. The term "Darwin's finches" was first applied by Percy Lowe in 1936, and popularised in 1947 by David Lack in his book ''Darwin's Finches''. Lack based his analysis on the large collectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pith
Pith, or medulla, is a tissue in the stems of vascular plants. Pith is composed of soft, spongy parenchyma cells, which in some cases can store starch. In eudicotyledons, pith is located in the center of the stem. In monocotyledons, it extends also into flowering stems and roots. The pith is encircled by a ring of xylem; the xylem, in turn, is encircled by a ring of phloem. While new pith growth is usually white or pale in color, as the tissue ages it commonly darkens to a deeper brown color. In trees pith is generally present in young growth, but in the trunk and older branches the pith often gets replaced – in great part – by xylem. In some plants, the pith in the middle of the stem may dry out and disintegrate, resulting in a hollow stem. A few plants, such as walnuts, have distinctive chambered pith with numerous short cavities (See image at middle right). The cells in the peripheral parts of the pith may, in some plants, develop to be different from cells in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic (ecology)
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example ''Cytisus aeolicus'' is an endemite of the Italian flora. ''Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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