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Xylosma Parvifolia
''Xylosma parvifolia'', commonly known as mountain xylosma, is a plant in the family Salicaceae. It is endemic to the mountains of Australia's Lord Howe Island in the Tasman Sea. Description Mountain xylosma is a shrub that grows to 2 m in height. Its leaves are rounded, 12 mm long by 8 mm wide, with toothed margins. The fruits are globular, purple and 5 mm in diameter; they are eaten, and the seeds dispersed, by birds. Distribution and habitat The plant is largely restricted to low shrub vegetation growing on narrow, exposed, southeasterly or southwesterly ridges off the two mountains – Mounts Lidgbird and Gower – in the southern part of the island. The known range lies within Lord Howe's Permanent Park Preserve. Status and conservation Fewer than 100 mature plants are known and, extrapolating to suitable habitat, fewer than 250 mature plants are likely to exist in the wild. Because of its small population size, limited habitat and susceptibility t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salicaceae
The Salicaceae is the willow family of flowering plants. The traditional family (Salicaceae ''sensu stricto'') included the willows, poplar, aspen, and cottonwoods. Genetic studies summarized by the Angiosperm Phylogeny Group (APG) have greatly expanded the circumscription of the family to contain 56 genera and about 1220 species, including the Scyphostegiaceae and many of the former Flacourtiaceae. In the Cronquist system, the Salicaceae were assigned to their own order, Salicales, and contained three genera (''willow, Salix'', ''Populus'', and ''Chosenia''). Recognized to be closely related to the Violaceae and Passifloraceae, the family is placed by the APG in the order Malpighiales. Under the new circumscription, all members of the family are trees or shrubs that have Simple leaf, simple leaves with Phyllotaxis, alternate arrangement and temperate members are usually deciduous. Most members have serrate or dentate leaf margins, and those that have such toothed margins all e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, smaller islands. With an area of , Australia is the largest country by area in Oceania and the world's List of countries and dependencies by area, sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a Megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and climates, with Deserts of Australia, deserts in the centre, tropical Forests of Australia, rainforests in the north-east, and List of mountains in Australia, mountain ranges in the south-east. The ancestors of Aboriginal Australians began arriving from south east Asia approximately Early human migrations#Nearby Oceania, 65,000 years ago, during the Last Glacial Period, last i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lord Howe Island
Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland Port Macquarie, northeast of Sydney, and about southwest of Norfolk Island. It is about long and between wide with an area of , though just of that comprise the low-lying developed part of the island. Along the west coast is a sandy semi-enclosed sheltered coral reef lagoon. Most of the population lives in the north, while the south is dominated by forested hills rising to the highest point on the island, Mount Gower (). The Lord Howe Island Group comprises 28 islands, islets, and rocks. Apart from Lord Howe Island itself, the most notable of these is the volcanic and uninhabited Ball's Pyramid about to the southeast of Howe. To the north lies a cluster of seven small uninhabited islands called the Admiralty Group. The first repo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tasman Sea
The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abel Janszoon Tasman, who in 1642 was the first known person to cross it. British explorer Lieutenant James Cook later extensively navigated the Tasman Sea in the 1770s during his three voyages of exploration. The Tasman Sea is informally referred to in both Australian and New Zealand English as the Ditch; for example, "crossing the Ditch" means travelling to Australia from New Zealand, or vice versa. The diminutive term "the Ditch" used for the Tasman Sea is comparable to referring to the North Atlantic Ocean as "the Pond". Climate The south of the sea is passed over by depressions going from west to east. The northern limit of these westerly winds is near to 40°S. During the southern winter, from April to October, the northern branch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaf
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the shoot system. In most leaves, the primary photosynthetic tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf but in some species, including the mature foliage of ''Eucalyptus'', palisade mesophyll is present on both sides and the leaves are said to be isobilateral. Most leaves are flattened and have distinct upper (adaxial) and lower ( abaxial) surfaces that differ in color, hairiness, the number of stomata (pores that intake and output gases), the amount and structure of epicuticular wax and other features. Leaves are mostly green in color due to the presence of a compound called chlorophyll that is essential for photosynthesis as it absorbs light ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Lidgbird
Mount Lidgbird, also Mount Ledgbird and Big Hill, is located in the southern section of Lord Howe Island, just north of Mount Gower, from which it is separated by the saddle at the head of Erskine Valley, and has its peak at above sea level. The trek to the summit is for expert climbers only. Ropes are needed to scale the cliffs and slippery, steep terrain. In comparison, Mount Gower is an easy hike. Halfway up the mountain is Goat House Cave, a former shelter for 19th-century Kentia palm gatherers. From this spot, visitors can see nesting masked boobies and numerous red-tailed tropicbirds. Etymology Mount Lidgbird is named by the naval officer Captain Henry Lidgbird Ball in honour of his father, George Lidgbird Ball. Ball junior first sighted Lord Howe Island in 1788 while he was on his way to Norfolk Island in the ship HMS ''Supply''. He also named the nearby rock outcrop Ball's Pyramid. Flora ''Cryptocarya'' forest, one of two types found on the island, the other be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Gower
Mount Gower (also known as Big Hill), is the highest mountain on Australia's subtropical Lord Howe Island in the Tasman Sea. With a height of above sea level, and a relatively flat summit plateau, it stands at the southern end of Lord Howe, just south of the island's second highest peak, the high Mount Lidgbird, from which it is separated by the saddle at the head of Erskine Valley. Ascending Gower entails a popular, guided, strenuous 8-hour return hike, though no special climbing skills are needed. The mountain is covered with rainforest, including cloud forest at the summit, containing many of the island's endemic plants. See also *List of mountains in Australia This is a list of mountains in Australia. Highest points by state and territory List of mountains in Australia by topographic prominence This is a list of the top 50 mountains in Australia ranked by topographic prominence. Most of these ... References Geography of Lord Howe Island Mountains of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stochastic Process
In probability theory and related fields, a stochastic () or random process is a mathematical object usually defined as a family of random variables. Stochastic processes are widely used as mathematical models of systems and phenomena that appear to vary in a random manner. Examples include the growth of a bacterial population, an electrical current fluctuating due to thermal noise, or the movement of a gas molecule. Stochastic processes have applications in many disciplines such as biology, chemistry, ecology, neuroscience, physics, image processing, signal processing, control theory, information theory, computer science, cryptography and telecommunications. Furthermore, seemingly random changes in financial markets have motivated the extensive use of stochastic processes in finance. Applications and the study of phenomena have in turn inspired the proposal of new stochastic processes. Examples of such stochastic processes include the Wiener process or Brownian motion process, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endangered Species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and invasive species. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration. Human activity is a significant cause in causing some species to become endangered. Conservation status The conservation status of a species indicates the likelihood that it will become extinct. Multiple factors are considered when assessing the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylosma
''Xylosma'' is a genus of flowering plants in the family Salicaceae. It contains around 100 species of evergreen shrubs and trees commonly known as brushhollies, xylosmas, or, more ambiguously, " logwoods". The generic name is derived from the Greek words ξύλον (''xylon''), meaning "wood," and ὀσμή (''osmé''), meaning "smell," referring to the fragrant wood of some of the species. The Takhtajan system places it in the family Flacourtiaceae, which is considered defunct by the Angiosperm Phylogeny Group. Description The leaves are alternate, simple, entire or finely toothed, long. The flowers are small, yellowish, produced on racemes long, usually dioecious, and have a strong scent. The fruit is a small purple-black berry in diameter that contains 2 to 8 seeds. Range The genus is predominantly native to the tropics and subtropics, from the Caribbean, Central America, northern South America, the Pacific Islands, southern Asia and northern Australasia. Two spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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