|
Orites Diversifolia
''Orites diversifolia (=diversifolius)'', commonly known as variable orites, is a member of the family Proteaceae and is endemic to Tasmania.Understorey Network. (2017). Orites diversifolius. [online] Available at: http://www.understorey-network.org.au/family-index.html?species=Orites%20diversifolius [Accessed 7 Mar. 2017]. The common name stems from the variable form of the leaves, which range from entire and linear to serrated and ovate. It is a common shrub in lowland rainforest, subalpine woodland and scrub. Taxonomy ''Orites'' is a genus of the family Proteaceae and is one of twelve Tasmanian genera. Within the genus there are nine species, of which seven are Australian endemics. The remaining two species are South American, located in Bolivia and the Chilean Andes respectively.George, A. and Hyland, B. (1995). Orites. In: Flora of Australia: Volume 16 Elaeagnaceae, Proteaceae 1, 1st ed. Melbourne: CSIRO Australia, pp.346-349. Four Australian endemics, ''Orites acicularis, Or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Brown (botanist, Born 1773)
Robert Brown (21 December 1773 – 10 June 1858) was a Scottish botanist and paleobotanist who made important contributions to botany largely through his pioneering use of the microscope. His contributions include one of the earliest detailed descriptions of the cell nucleus and cytoplasmic streaming; the observation of Brownian motion; early work on plant pollination and fertilisation, including being the first to recognise the fundamental difference between gymnosperms and angiosperms; and some of the earliest studies in palynology. He also made numerous contributions to plant taxonomy, notably erecting a number of plant families that are still accepted today; and numerous Australian plant genera and species, the fruit of his exploration of that continent with Matthew Flinders. Early life Robert Brown was born in Montrose on 21 December 1773, in a house that existed on the site where Montrose Library currently stands. He was the son of James Brown, a minister in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Field National Park
Mount Field National Park is a national park in Tasmania, Australia, 64 km northwest of Hobart. The landscape ranges from eucalyptus temperate rainforest to alpine moorland, rising to 1,434 metres (4,705 ft) at the summit of Mount Field West. History Mount Field National Park was founded in 1916, making it, along with Freycinet National Park, Tasmania's oldest national park. The area around Russell Falls has been protected for its natural beauty since 1885, when it was set aside as Tasmania's first nature reserve. The last known wild thylacine was captured in the region in 1933. The reserve was called "National Park" before 1946, but was officially renamed to its present name in 1947. Etymology Mount Field National Park was named for Judge Barron Field, who visited Tasmania as an itinerant judge in 1819 and 1821. Geology During the Pleistocene period, a snowfield covered the top of the Mount Field plateau and fed glaciers in the surrounding valleys. A large, 12&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vicariance
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow. Various geographic changes can arise such as the movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations. These factors can substantially alter a region's geography, resulting in the separation of a species population into isolated subpopulations. The vicariant populations then undergo genetic changes as they become subjected to different selective pressures, experience genetic drift, and accumulate different mutations in the separated populations' gene pools. The barriers prevent the exchange of genetic information between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwanan
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous Period, it merged with Laurasia to form a larger supercontinent called Pangaea. Gondwana (and Panga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated ( S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now called si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diploid
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more chromosome sets. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an organism's life cycle. Half ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptospermum
''Leptospermum'' is a genus of shrubs and small trees in the myrtle family Myrtaceae commonly known as tea trees, although this name is sometimes also used for some species of ''Melaleuca''. Most species are endemic to Australia, with the greatest diversity in the south of the continent, but some are native to other parts of the world, including New Zealand and Southeast Asia. Leptospermums all have five conspicuous petals and five groups of stamens which alternate with the petals. There is a single style in the centre of the flower and the fruit is a woody capsule. The first formal description of a leptospermum was published in 1776 by the German botanists Johann Reinhold Forster and his son Johann Georg Adam Forster, but an unambiguous definition of individual species in the genus was not achieved until 1979. Leptospermums grow in a wide range of habitats but are most commonly found in moist, low-nutrient soils. They have important uses in horticulture, in the production of h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eucryphia
''Eucryphia'' is a small genus of trees and large shrubs native to the south temperate regions of South America and coastal eastern Australia, mainly Tasmania. Sometimes placed in a family of their own, the Eucryphiaceae, more recent classifications place them in the Cunoniaceae. There are seven species, two in South America and five in Australia, and several named hybrids. Description They are mostly evergreen though one species (''E. glutinosa'') is usually deciduous. The leaves are opposite, and either simple or pinnate with 3-13 leaflets. The flowers are produced in late summer or autumn, are showy and sweetly scented, 3–6 cm diameter, with four creamy-white petals, and numerous stamens and styles. The fruit is a woody capsule 1-1.5 cm long containing several seeds, and maturing in 12–15 months. Etymology The generic name ''Eucryphia'' is composed of two parts, namely ''eu-'' and ''-cryphia''. The Greek ευ-κρυφαιος means well-covered and refers t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nothofagus
''Nothofagus'', also known as the southern beeches, is a genus of 43 species of trees and shrubs native to the Southern Hemisphere in southern South America (Chile, Argentina) and Australasia (east and southeast Australia, New Zealand, New Guinea, and New Caledonia). The species are ecological dominants in many temperate forests in these regions. Some species are reportedly naturalised in Germany and Great Britain. The genus has a rich fossil record of leaves, cupules, and pollen, with fossils extending into the late Cretaceous period and occurring in Australia, New Zealand, Antarctica, and South America. Description The leaves are toothed or entire, evergreen or deciduous. The fruit is a small, flattened or triangular nut, borne in cupules containing one to seven nuts. Reproduction Many individual trees are extremely old, and at one time, some populations were thought to be unable to reproduce in present-day conditions where they were growing, except by suckering ( clonal rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllocladus Aspleniifolius
''Phyllocladus aspleniifolius'', commonly known as the celerytop pine, is an endemic gymnosperm of Tasmania, Australia. It is widespread and common in Tasmania, with the most abundance in the western highlands. Its ‘leaves’ appear similar to those of a celery plant, hence the common name. Description ''Phyllocladus aspeniifolius'' is a large, conical conifer in the family Podocarpaceae. The trunk is erect with horizontal branches. True leaves appear at the seedling stage and are fine and needle-like. Mature leaves are reduced to minute, brown scales. The function of the leaf is taken over by cladodes that look like green diamond shaped leaves, similar to the leaves of a celery plant, hence the common name “celery-top pine”. The cladodes are thick and flattened, 3–8 cm long borne spirally on green stems. The plant may bear male and female cones on the same tree or separate trees in summer. The male cones are cylindrical, 3–5 mm long, with 2-3 together ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atherosperma Moschatum
''Atherosperma moschatum'', the southern sassafras or blackheart sassafras, is an evergreen tree native to the cool temperate rainforests of Tasmania, Victoria, and New South Wales in Australia. It is common in the rainforests of Tasmania and Victoria, but more scattered and rare in the higher altitudes of eastern New South Wales. The northernmost area is at Mount Grundy, west of Port Macquarie. Taxonomy The southern sassafras was first described by French naturalist Jacques Labillardière in 1806, and was the only member of the genus ''Atherosperma''. A subspecies, ''A. m.'' subsp.'' integrifolium'', has been considered a separate species. Its generic name is derived from the Ancient Greek ''ather'' "awn", and ''sperma'' "seed", from the hairs on the fruit, and the specific epithet ''moschatum'' is the Latin adjective meaning "musk-scented", from the smell of the bark. It is a member of the small family Atherospermataceae along with several other Australian rainforest trees inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Robert Brown (botanist, Born 1773)")
