Western Australia is a state occupying the entire western third of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, South Australia to the south-east. Western Australia is Australia's largest state, with a total land area of 2,529,875 square kilometres, the second-largest country subdivision in the world, surpassed only by Russia's Sakha Republic; the state has about 2.6 million inhabitants – around 11 percent of the national total – of whom the vast majority live in the south-west corner, 79 per cent of the population living in the Perth area, leaving the remainder of the state sparsely populated. The first European visitor to Western Australia was the Dutch explorer Dirk Hartog, who visited the Western Australian coast in 1616; the first European settlement of Western Australia occurred following the landing by Major Edmund Lockyer on 26 December 1826 of an expedition on behalf of the New South Wales colonial government.
He established a convict-supported military garrison at King George III Sound, at present-day Albany, on 21 January 1827 formally took possession of the western third of the continent for the British Crown. This was followed by the establishment of the Swan River Colony in 1829, including the site of the present-day capital, Perth. York was the first inland settlement in Western Australia. Situated 97 kilometres east of Perth, it was settled on 16 September 1831. Western Australia achieved responsible government in 1890 and federated with the other British colonies in Australia in 1901. Today, its economy relies on mining, agriculture and tourism; the state produces 46 per cent of Australia's exports. Western Australia is the second-largest iron ore producer in the world. Western Australia is bounded to the east by longitude 129°E, the meridian 129 degrees east of Greenwich, which defines the border with South Australia and the Northern Territory, bounded by the Indian Ocean to the west and north.
The International Hydrographic Organization designates the body of water south of the continent as part of the Indian Ocean. The total length of the state's eastern border is 1,862 km. There are 20,781 km including 7,892 km of island coastline; the total land area occupied by the state is 2.5 million km2. The bulk of Western Australia consists of the old Yilgarn craton and Pilbara craton which merged with the Deccan Plateau of India and the Karoo and Zimbabwe cratons of Southern Africa, in the Archean Eon to form Ur, one of the oldest supercontinents on Earth. In May 2017, evidence of the earliest known life on land may have been found in 3.48-billion-year-old geyserite and other related mineral deposits uncovered in the Pilbara craton. Because the only mountain-building since has been of the Stirling Range with the rifting from Antarctica, the land is eroded and ancient, with no part of the state above 1,245 metres AHD. Most of the state is a low plateau with an average elevation of about 400 metres low relief, no surface runoff.
This descends sharply to the coastal plains, in some cases forming a sharp escarpment. The extreme age of the landscape has meant that the soils are remarkably infertile and laterised. Soils derived from granitic bedrock contain an order of magnitude less available phosphorus and only half as much nitrogen as soils in comparable climates in other continents. Soils derived from extensive sandplains or ironstone are less fertile, nearly devoid of soluble phosphate and deficient in zinc, copper and sometimes potassium and calcium; the infertility of most of the soils has required heavy application by farmers of fertilizers. These have resulted in damage to bacterial populations; the grazing and use of hoofed mammals and heavy machinery through the years have resulted in compaction of soils and great damage to the fragile soils. Large-scale land clearing for agriculture has damaged habitats for native fauna; as a result, the South West region of the state has a higher concentration of rare, threatened or endangered flora and fauna than many areas of Australia, making it one of the world's biodiversity "hot spots".
Large areas of the state's wheatbelt region have problems with dryland salinity and the loss of fresh water. The southwest coastal area has a Mediterranean climate, it was heavily forested, including large stands of karri, one of the tallest trees in the world. This agricultural region is one of the nine most bio-diverse terrestrial habitats, with a higher proportion of endemic species than most other equivalent regions. Thanks to the offshore Leeuwin Current, the area is one of the top six regions for marine biodiversity and contains the most southerly coral reefs in the world. Average annual rainfall varies from 300 millimetres at the edge of the Wheatbelt region to 1,400 millimetres in the wettest areas near Northcliffe, but from November to March, evaporation exceeds rainfall, it is very dry. Plants are adapted to this as well as the extreme poverty of all soils; the central two-thirds of the state is sparsely inhabited. The only significant economic activity is mining. Annual rainfall averages less than 300 millimetres, most of which occurs in sporadic torrential falls related to cyclone events in summer.
An exception to this is
The flowering plants known as angiosperms, Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 64 orders, 416 families 13,164 known genera and c. 369,000 known species. Like gymnosperms, angiosperms are seed-producing plants. However, they are distinguished from gymnosperms by characteristics including flowers, endosperm within the seeds, the production of fruits that contain the seeds. Etymologically, angiosperm means a plant; the term comes from the Greek words sperma. The ancestors of flowering plants diverged from gymnosperms in the Triassic Period, 245 to 202 million years ago, the first flowering plants are known from 160 mya, they diversified extensively during the Early Cretaceous, became widespread by 120 mya, replaced conifers as the dominant trees from 100 to 60 mya. Angiosperms differ from other seed plants in several ways, described in the table below; these distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants and the most commercially important group to humans.
Angiosperm stems are made up of seven layers. The amount and complexity of tissue-formation in flowering plants exceeds that of gymnosperms; the vascular bundles of the stem are arranged such that the phloem form concentric rings. In the dicotyledons, the bundles in the young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium. By the formation of a layer of cambium between the bundles, a complete ring is formed, a regular periodical increase in thickness results from the development of xylem on the inside and phloem on the outside; the soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Owing to differences in the character of the elements produced at the beginning and end of the season, the wood is marked out in transverse section into concentric rings, one for each season of growth, called annual rings.
Among the monocotyledons, the bundles are more numerous in the young stem and are scattered through the ground tissue. They once formed the stem increases in diameter only in exceptional cases; the characteristic feature of angiosperms is the flower. Flowers show remarkable variation in form and elaboration, provide the most trustworthy external characteristics for establishing relationships among angiosperm species; the function of the flower is to ensure fertilization of the ovule and development of fruit containing seeds. The floral apparatus may arise terminally from the axil of a leaf; as in violets, a flower arises singly in the axil of an ordinary foliage-leaf. More the flower-bearing portion of the plant is distinguished from the foliage-bearing or vegetative portion, forms a more or less elaborate branch-system called an inflorescence. There are two kinds of reproductive cells produced by flowers. Microspores, which will divide to become pollen grains, are the "male" cells and are borne in the stamens.
The "female" cells called megaspores, which will divide to become the egg cell, are contained in the ovule and enclosed in the carpel. The flower may consist only of these parts, as in willow, where each flower comprises only a few stamens or two carpels. Other structures are present and serve to protect the sporophylls and to form an envelope attractive to pollinators; the individual members of these surrounding structures are known as petals. The outer series is green and leaf-like, functions to protect the rest of the flower the bud; the inner series is, in general, white or brightly colored, is more delicate in structure. It functions to attract bird pollinators. Attraction is effected by color and nectar, which may be secreted in some part of the flower; the characteristics that attract pollinators account for the popularity of flowers and flowering plants among humans. While the majority of flowers are perfect or hermaphrodite, flowering plants have developed numerous morphological and physiological mechanisms to reduce or prevent self-fertilization.
Heteromorphic flowers have short carpels and long stamens, or vice versa, so animal pollinators cannot transfer pollen to the pistil. Homomorphic flowers may employ a biochemical mechanism called self-incompatibility to discriminate between self and non-self pollen grains. In other species, the male and female parts are morphologically separated, developing on different flowers; the botanical term "Angiosperm", from the Ancient Greek αγγείον, angeíon and σπέρμα, was coined in the form Angiospermae by Paul Hermann in 1690, as the name of one of his primary divisions of the plant kingdom. This included flowering plants possessing seeds enclosed in capsules, distinguished from his Gymnospermae, or flowering plants with achenial or schizo-carpic fruits, the whole fruit or each of its pieces being here regarded as a seed and naked; the term and its antonym were maintained by Carl Linnaeus with the same sense, but with restricted application, in the names of the orders of his class Didynamia. Its use with any
Department of Parks and Wildlife (Western Australia)
The Department of Parks and Wildlife was the department of the Government of Western Australia responsible for managing lands described in the Conservation and Land Management Act 1984 and implementing the state's conservation and environment legislation and regulations. The minister responsible for the department was the Minister for the Environment; the Department of Environment and Conservation was separated on 30 June 2013, forming the Department of Parks and Wildlife and the Department of Environment Regulation, both of which commenced operations on 1 July 2013. DPaW focused on managing national parks, marine parks and reserves. DER focused on environmental regulation and appeals processes, pollution prevention, it was announced on 28 April 2017 that the Department of Parks and Wildlife would merge with the Botanic Gardens and Parks Authority, the Zoological Parks Authority, the Rottnest Island Authority on 1 July 2017 to form the Department of Biodiversity and Attractions. The Department of Parks and Wildlife had management responsibilities in: nature reserves 100 national parks 19 conservation parks 17 marine parks 1 marine nature reserve 2 marine management areas State forests and other lands and waters throughout the stateAt 30 June 2017, the total area under Parks and Wildlife's care was 31,480,868 ha.
The land area managed by the Department was about 10.6 per cent of the land area of Western Australia. The lands and waters managed by the Department received in 2014-15 18.6 million visits a year, with visitor satisfaction at a high level of 89%. The average level of visitor satisfaction with their visit on Parks & Wildlife lands and waters was of 91.4% in 2015-16. Western Australian national parks and reserves received 20 million visits in a single year for the first time in 2016–17 and a visitor satisfaction level of 92.5 per cent. Each year Parks and Wildlife aimed for a satisfaction rating above 85 per cent, a figure it had achieved for more than 10 consecutive years. 10,910 people were registered volunteers with the Department in 2014-15 that helped in a range of projects across the State with 610,000 hours contributed. During 2015-16, 5,189 active volunteers of the total 13,737 registered individuals contributed 638,747 voluntary hours to more than 200 Parks and Wildlife environmental and recreational programs.
In 2016-17, Parks and Wildlife's volunteers have contributed to a record number of hours to help conserve and manage WA’s natural places, with 5,410 volunteers contributing 723,508 hours. Parks and Wildlife was responsible for the wildlife conservation project Western Shield, a pest animal and weed control program that included 4 million hectares of conservation reserves and State forests baited for feral animal control, as well as weed control on more than 89 million hectares of unallocated Crown land and unmanaged reserves. There are a number of internationally recognised biodiversity hotspots within Western Australia and in particular in the south west of the state. Parks and Wildlife managed two long distance trails: the 1,000 km Bibbulmun Track for walkers, the 1,000 km Munda Biddi Trail for cyclists. An important duty of the Department was to be responsible for bushfire prevention and suppression on its lands as well as fire prevention in unallocated Crown land and unmanaged reserves.
This included conducting controlled burns to reduced fuel load, research into the behaviour and effects of bushfires. More than 247,360 hectares were prescribed burnt in the three forest regions during the 2016-17 financial year, in addition to the significant burns that have been undertaken by staff in the South Coast, Wheatbelt, Mid West and Kimberley regions up to 2,988,394 hectares; some of the most severe West Australian bushfires that the Department had to suppress, in chronological order, include: Earlier forms of Nature conservation in Western Australia were under: Department of Lands and Surveys: 1 January 1890 - 31 December 1895 Wood and Forests Department: 1 January 1896 – 31 December 1918 Forests Department: 1 January 1919 – 21 March 1985 State Gardens Board: 15 December 1920 – 30 April 1957 National Parks Board: 1 May 1957 – 30 July 1977 Department of Fisheries and Fauna: 1 October 1964 – 31 December 1973 National Parks Authority: 1 August 1977 – 15 April 1985 National Parks Authority Wildlife section of the Department of Fisheries and Wildlife: 1 January 1974 – 21 March 1985 Department of Fisheries and Wildlife Department of Conservation and Land Management: 22 March 1985 – 30 June 2006 Department of Environment and Conservation: 1 July 2006 – 30 June 2013 Swan River Trust: 1989 - 1 July 2015 The Department maintained and coordinated a range of specialist equipment and emergency response vehicles.
This included pumpers and tankers and other equipment relating to operations involving search and rescue and firefighting. The Department of Parks and Wildlife had 3 types of uniforms: a standard khaki and bottle green uniform with appropriate badging was supplied to and worn by staff whose duties included the monitoring of legislative compliance, a work wear for those that worked in the field and personal protective equipment or clothing (TecaSafe gold overshirt, TecaSafe dark green trouse
In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a woody trunk and branches as a way to tower above other plants to compete for sunlight. Trees tend to be long-lived, some reaching several thousand years old. In wider definitions, the taller palms, tree ferns and bamboos are trees. Trees have been in existence for 370 million years, it is estimated. A tree has many secondary branches supported clear of the ground by the trunk; this trunk contains woody tissue for strength, vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark. Below the ground, the roots spread out widely. Above ground, the branches divide into smaller shoots.
The shoots bear leaves, which capture light energy and convert it into sugars by photosynthesis, providing the food for the tree's growth and development. Trees reproduce using seeds. Flowers and fruit may be present, but some trees, such as conifers, instead have pollen cones and seed cones. Palms and bamboos produce seeds, but tree ferns produce spores instead. Trees play a significant role in moderating the climate, they remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissues. Trees and forests provide a habitat for many species of plants. Tropical rainforests are among the most biodiverse habitats in the world. Trees provide shade and shelter, timber for construction, fuel for cooking and heating, fruit for food as well as having many other uses. In parts of the world, forests are shrinking as trees are cleared to increase the amount of land available for agriculture; because of their longevity and usefulness, trees have always been revered, with sacred groves in various cultures, they play a role in many of the world's mythologies.
Although "tree" is a term of common parlance, there is no universally recognised precise definition of what a tree is, either botanically or in common language. In its broadest sense, a tree is any plant with the general form of an elongated stem, or trunk, which supports the photosynthetic leaves or branches at some distance above the ground. Trees are typically defined by height, with smaller plants from 0.5 to 10 m being called shrubs, so the minimum height of a tree is only loosely defined. Large herbaceous plants such as papaya and bananas are trees in this broad sense. A applied narrower definition is that a tree has a woody trunk formed by secondary growth, meaning that the trunk thickens each year by growing outwards, in addition to the primary upwards growth from the growing tip. Under such a definition, herbaceous plants such as palms and papayas are not considered trees regardless of their height, growth form or stem girth. Certain monocots may be considered trees under a looser definition.
Aside from structural definitions, trees are defined by use. The tree growth habit is an evolutionary adaptation found in different groups of plants: by growing taller, trees are able to compete better for sunlight. Trees tend some reaching several thousand years old. Several trees are among the oldest organisms now living. Trees have modified structures such as thicker stems composed of specialised cells that add structural strength and durability, allowing them to grow taller than many other plants and to spread out their foliage, they differ from shrubs, which have a similar growth form, by growing larger and having a single main stem. The tree form has evolved separately in unrelated classes of plants in response to similar environmental challenges, making it a classic example of parallel evolution. With an estimated 60,000-100,000 species, the number of trees worldwide might total twenty-five per cent of all living plant species; the greatest number of these grow in tropical regions and many of these areas have not yet been surveyed by botanists, making tree diversity and ranges poorly known.
The majority of tree species are angiosperms. There are about 1000 species of gymnosperm trees, including conifers, cycads and gnetales. Most angiosperm trees are eudicots, the "true dicotyledons", so named because the seeds contain two cotyledons or seed leaves. There are some trees among the old lineages of flowering plants called basal angiosperms or paleodicots. Wood gives structural strength to the trunk of most types of tree; the vascular system of trees allows water and other chemicals to be di
South Australia is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of 983,482 square kilometres, it is the fourth-largest of Australia's states and territories by area, fifth largest by population, it has a total of 1.7 million people, its population is the second most centralised in Australia, after Western Australia, with more than 77 percent of South Australians living in the capital, Adelaide, or its environs. Other population centres in the state are small. South Australia shares borders with all of the other mainland states, with the Northern Territory; the state comprises less than 8 percent of the Australian population and ranks fifth in population among the six states and two territories. The majority of its people reside in greater Metropolitan Adelaide. Most of the remainder are settled in fertile areas along River Murray; the state's colonial origins are unique in Australia as a settled, planned British province, rather than as a convict settlement.
Colonial government commenced on 28 December 1836, when the members of the council were sworn in near the Old Gum Tree. As with the rest of the continent, the region had been long occupied by Aboriginal peoples, who were organised into numerous tribes and languages; the South Australian Company established a temporary settlement at Kingscote, Kangaroo Island, on 26 July 1836, five months before Adelaide was founded. The guiding principle behind settlement was that of systematic colonisation, a theory espoused by Edward Gibbon Wakefield, employed by the New Zealand Company; the goal was to establish the province as a centre of civilisation for free immigrants, promising civil liberties and religious tolerance. Although its history is marked by economic hardship, South Australia has remained politically innovative and culturally vibrant. Today, it is known for numerous cultural festivals; the state's economy is dominated by the agricultural and mining industries. Evidence of human activity in South Australia dates back as far as 20,000 years, with flint mining activity and rock art in the Koonalda Cave on the Nullarbor Plain.
In addition wooden spears and tools were made in an area now covered in peat bog in the South East. Kangaroo Island was inhabited; the first recorded European sighting of the South Australian coast was in 1627 when the Dutch ship the Gulden Zeepaert, captained by François Thijssen and mapped a section of the coastline as far east as the Nuyts Archipelago. Thijssen named the whole of the country eastward of the Leeuwin "Nuyts Land", after a distinguished passenger on board; the coastline of South Australia was first mapped by Matthew Flinders and Nicolas Baudin in 1802, excepting the inlet named the Port Adelaide River, first discovered in 1831 by Captain Collet Barker and accurately charted in 1836–37 by Colonel William Light, leader of the South Australian Colonization Commissioners"First Expedition' and first Surveyor-General of South Australia. The land which now forms the state of South Australia was claimed for Britain in 1788 as part of the colony of New South Wales. Although the new colony included two-thirds of the continent, early settlements were all on the eastern coast and only a few intrepid explorers ventured this far west.
It took more than forty years before any serious proposal to establish settlements in the south-western portion of New South Wales were put forward. On 15 August 1834, the British Parliament passed the South Australia Act 1834, which empowered His Majesty to erect and establish a province or provinces in southern Australia; the act stated that the land between 132° and 141° east longitude and from 26° south latitude to the southern ocean would be allotted to the colony, it would be convict-free. In contrast to the rest of Australia, terra nullius did not apply to the new province; the Letters Patent, which used the enabling provisions of the South Australia Act 1834 to fix the boundaries of the Province of South Australia, provided that "nothing in those our Letters Patent shall affect or be construed to affect the rights of any Aboriginal Natives of the said Province to the actual occupation and enjoyment in their own Persons or in the Persons of their Descendants of any Lands therein now occupied or enjoyed by such Natives."
Although the patent guaranteed land rights under force of law for the indigenous inhabitants it was ignored by the South Australian Company authorities and squatters. Survey was required before settlement of the province, the Colonization Commissioners for South Australia appointed William Light as the leader of its'First Expedition', tasked with examining 1500 miles of the South Australian coastline and selecting the best site for the capital, with planning and surveying the site of the city into one-acre Town Sections and its surrounds into 134-acre Country Sections. Eager to commence the establishment of their whale and seal fisheries, the South Australian Company sought, obtained, the Commissioners' permission to send Company ships to South Australia, in advance of the surveys and ahead of the Commissioners' colonists; the Company's settlement of seven vessels and 636 people was temporarily made at Kingscote on Kangaroo Island, until
Flora of Australia
The flora of Australia comprises a vast assemblage of plant species estimated to over 20,000 vascular and 14,000 non-vascular plants, 250,000 species of fungi and over 3,000 lichens. The flora has strong affinities with the flora of Gondwana, below the family level has a endemic angiosperm flora whose diversity was shaped by the effects of continental drift and climate change since the Cretaceous. Prominent features of the Australian flora are adaptations to aridity and fire which include scleromorphy and serotiny; these adaptations are common in species from the large and well-known families Proteaceae and Fabaceae. The arrival of humans around 50,000 years ago and settlement by Europeans from 1788, has had a significant impact on the flora; the use of fire-stick farming by Aboriginal people led to significant changes in the distribution of plant species over time, the large-scale modification or destruction of vegetation for agriculture and urban development since 1788 has altered the composition of most terrestrial ecosystems, leading to the extinction of 61 plant species and endangering over 1000 more.
Austrial major commonwealth foundations Australia was part of the southern supercontinent Gondwana, which included South America, Africa and Antarctica. Most of the modern Australian flora had their origin in Gondwana during the Cretaceous when Australia was covered in subtropical rainforest. Australian ferns and gymnosperm bear strong resemblance to their Gondwanan ancestors, prominent members of the early Gondwanan angiosperm flora such as the Nothofagus and Proteaceae were present in Australia. Gondwana began to break up 140 million years ago; as Australia drifted and global climate change had a significant and lasting effect: a circumpolar oceanic current developed, atmospheric circulation increased as Australia moved away from Antarctica, precipitation fell, there was a slow warming of the continent and arid conditions started to develop. These conditions of geographic isolation and aridity led to the development of a more complex flora. From 25-10 MYA pollen records suggest the rapid radiation of species like Eucalyptus, Allocasuarina and the pea-flowered legumes, the development of open forest.
Collision with the Eurasian Plate led to additional South-east Asian and cosmopolitan elements entering the flora like the Lepidium and Chenopodioideae. The development of aridity and the old and nutrient poor soils of the continent led to some unique adaptations in the Australian flora and evolutionary radiation of genera – like Acacia and Eucalyptus – that adapted to those conditions. Hard leaves with a thick outer layer, a condition known as scleromorphy, C4 and CAM carbon fixation which reduce water loss during photosynthesis are two common adaptations in Australian arid-adapted dicot and monocot species respectively. Rising aridity increased the frequency of fires in Australia. Fire is thought to have played a role in the development and distribution of fire-adapted species from the Late Pleistocene. An increase in charcoal in sediment around 38,000 years ago coincides with dates for the inhabitation of Australia by the Indigenous Australians and suggests that man-made fires, from practices like fire-stick farming, have played an important role in the establishment and maintenance of sclerophyll forest on the east coast of Australia.
Adaptations to fire include lignotubers and epicormic buds in Eucalyptus and Banksia species that allow fast regeneration following fire. Some genera exhibit serotiny, the release of seed only in response to heat and/or smoke. Xanthorrhoea grass trees and some species of orchids only flower after fire. In biogeography and zoogeography, Australia alone is sometimes considered a realm, while some authors unite the area with other regions to form the Australasian realm. In phytogeography, the area is considered a floristic kingdom, with the following endemic families, according to Takhtajan: Platyzomataceae, Austrobaileyaceae, Gyrostemonaceae, Davidsoniaceae, Eremosynaceae, Emblingiaceae, Tremandraceae, Brunoniaceae, Doryanthaceae and Xanthorrhoeaceae, it is the center of origin of Eupomatiaceae, Epacridaceae, Stackhousiaceae and Goodeniaceae. Other families with high occurrences are Poaceae, Asteraceae, Euphorbiaceae, Rutaceae and Proteaceae. Australia's terrestrial flora can be collected into characteristic vegetation groups.
The most important determinant is rainfall, followed by temperature which affects water availability. Several schemes of varying complexity have been created, the most recent scheme developed by the Natural Heritage Trust divides Australia's terrestrial flora into 30 Major Vegetation Groups, 67 Major Vegetation Subgroups. According to the scheme the most common vegetation types are those that are adapted to arid conditions where the area has not been reduced by human activities such as land clearing for agriculture; the dominant vegetation type in Australia is the hummock grasslands that occur extensively in arid Western Australia, South Australia and the Northern Territory. It accounts for 23% of the native vegetation, the predominant species of which are from the genus Triodia. Zygochloa occurs in inland sandy areas like the Simpson Desert. A furt
The Mimosoideae are trees, herbs and shrubs that grow in tropical and subtropical climates. They comprise a clade placed at the subfamily or family level in the flowering plant family Fabaceae. In previous classifications, Mimosoideae refers to what was considered the tribe Mimoseae. Characteristics include flowers in radial symmetry with petals that are valvate in bud, have numerous showy, prominent stamens. Mimosoideae comprise 2,500 species; some classification systems, for example the Cronquist system, treat the Fabaceae in a narrow sense, raising the Mimisoideae to the rank of family as Mimosaceae. The Angiosperm Phylogeny Group treats Fabaceae in the broad sense; the Mimosoideae were subdivided into four tribes. However, modern molecular phylogenetics has shown. Several informal subgroups have been proposed, but not yet described formally as tribes. Additionally, the genus Acacia was segregated into five genera; the following fossil wood morphogenera have been described: Modern molecular phylogenetics suggests the following relationships: Acacieae is a wide-ranging, polyphyletic tribe of legumes in the Mimosoideae, native to the tropics and warm-temperate regions.
It includes six genera and some 1,450 species. Subdivision – 5 or 6 genera Acacia Mill. -- type genus Vachellia Arn. Senegalia Rafinesque Acaciella Britton & Rose Mariosousa Seigler & Ebinger Racosperma Martius In Bentham's 1842 circumscription of the subfamily Mimosoideae, Acacieae was one of its three constituent tribes, the others being Ingeae Benth. & Hook.f. and Mimoseae Bornn. His Acacieae tribe of 1842 included many genera that were subsequently assigned to tribe Ingeae Benth. In 1875, Bentham narrowed his definition of Acacieae so as to include only Acacia Mill; the only morphological character of Acacieae used to distinguish it from the Ingeae is the presence of free stamens. In the Ingeae they are fused in the form of a tube, whereas in the Acacieae only a few species have the stamens fused at the base. Several characters of the foliage, seed pods and stipules are shared by the two tribes; the flower morphology of Acacia s.l. has characteristics in common with the genera Leucaena and Mimosa and Enterolobium and Lysiloma.
The tribal position of monotypic genus Faidherbia A. Chevalier is equivocal, it was included in the Acacieae by Vassal and Maslin et al. but Lewis & Rico Arce placed it in tribe Ingeae following Polhill and Luckow et al.. In the latter case, tribe Acacieae may conform to genus Acacia s.l. pending the latter's relationship to other mimosoid genera. Faidherbia is troublesome as its stamens are shortly united at their base and its pollen is similar to some taxa in the Ingeae, they are shrubs or lianas, which may be armed or unarmed. Where they have spines, these are modified stipules. In some, prickles epidermis; the leaves are modified to vertically oriented phyllodes. A few have cladodes rather than leaves. Extrafloral nectaries may be present on the petiole and rachis, the pinnule tips may carry protein-lipid Beltian bodies; the leaflets are opposite, are carried on shortly stalks or are sessile. The heartwood is red and hard, the sap of various species hardens into gum; the inflorescences are dense pedunculate heads or spikes borne in axillary clusters, or are aggregated in terminal panicles.
The tetra - or pentamerous flowers are male and bisexual. Sepals are valvate; the reduced petals are valvate, or absent. The flowers have numerous exserted stamens, their filaments are sometimes connate at their base. Male flowers of some neotropical species have a reduced staminal tube. Flowers are yellow or cream-coloured, but may be white, red, or purple; the ovary is stipitate, with many ovules or ovules arranged in two rows. The ovary is attached by a filiform style to a capitate stigma; the legume's endocarp is attached to the exocarp, but is otherwise variable, may be dehiscent or indehiscent. Seeds are elliptic to oblong and flattened to varying degrees. Seeds have a hard black-brown testa with a pleurogram, visible as a closed or closed O-shaped line; some phyllodinous species have a colourful elaiosome on the seed. Data related to Acacieae at Wikispecies Media related to Mimosoideae at Wikimedia Commons