Acacia, commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially it comprised a group of plant species native to Africa and Australia, with the first species A. nilotica described by Linnaeus. Controversy erupted in the early 2000s when it became evident that the genus as it stood was not monophyletic, and that several divergent lineages needed to be placed in separate genera. It turned out that one lineage comprising over 900 species mainly native to Australia was not closely related to the mainly African lineage that contained A. nilotica—the first and type species. This meant that the Australian lineage (by far the most prolific in number of species) would need to be renamed. Botanist Les Pedley named this group Racosperma, which was inconsistently adopted. Australian botanists proposed that this would be more disruptive than setting a different type species (A. penninervis) and allowing this large number of species to remain Acacia, resulting in the two African lineages being renamed Vachellia and Senegalia, and the two New World lineages renamed Acaciella and Mariosousa. This was officially adopted, but many botanists from Africa and elsewhere disagreed that this was necessary.
A number of species have been introduced to various parts of the world, and two million hectares of commercial plantations have been established. The heterogeneous group varies considerably in habit, from mat-like subshrubs to canopy trees in forest.
|Range of the genus Acacia|
The genus was first described from Africa by C. F. P. von Martius in 1829. Several hundred combinations in Acacia were published by Pedley in 2003. The genus of 981 species, Acacia s.l., in the subfamily Mimosoideae of the pea family Fabaceae is monophyletic. All but 10 of its species are native to Australia, where it constitutes the largest plant genus.
Following a controversial decision to choose a new type for Acacia in 2005, the Australian component of Acacia s.l. now retains the name Acacia. At the 2011 International Botanical Congress held in Melbourne, the decision to use the name Acacia, rather than the proposed Racosperma for this genus, was upheld. Other Acacia s.l. taxa continue to be called Acacia by those who choose to consider the entire group as one genus.
Australian species of the genus Paraserianthes s.l. are deemed its closest relatives, particularly P. lophantha. The nearest relatives of Acacia and Paraserianthes s.l. in turn include the Australian and South East Asian genera Archidendron, Archidendropsis, Pararchidendron and Wallaceodendron, all of the tribe Ingeae.
The origin of "wattle" may be an Old Teutonic word meaning "to weave". From around 700 A.D. watul was used in Old English to refer to the interwoven branches and sticks which formed fences, walls and roofs. Since about 1810 it refers to the Australian legumes that provide these branches.
One species is native to Madagascar, one to Reunion island, 12 to Asia, and the remaining species (over 900) are native to Australasia and the Pacific Islands. These species were all given combinations by Pedley when he erected the genus Racosperma, hence Acacia pulchella, for example, became Racosperma pulchellum. However these were not upheld with the retypification of Acacia.
Acacias in Australia probably evolved their fire resistance about 20 million years ago when fossilised charcoal deposits show a large increase, indicating that fire was a factor even then. With no major mountain ranges or rivers to prevent their spread, the wattles began to spread all over the continent as it dried and fires became more common. They began to form dry, open forests with species of the genera Allocasuarina, Eucalyptus and Callitris (cypress-pines).
The southernmost species in the genus are Acacia dealbata (silver wattle), Acacia longifolia (coast wattle or Sydney golden wattle), Acacia mearnsii (black wattle), and Acacia melanoxylon (blackwood), reaching 43°30' S in Tasmania, Australia.
An Acacia-like 14 cm long fossil seed pod has been described from the Eocene of the Paris Basin. Acacia like fossil pods under the name Leguminocarpon are known from late Oligocene deposits at different sites in Hungary. Seed pod fossils of †Acacia parschlugiana and †Acacia cyclosperma are known from Tertiary deposits in Switzerland,. †Acacia colchica has been described from the Miocene of West Georgia. Pliocene fossil pollen of an Acacia sp. has been described from West Georgia and Abkhazia. Oldest records of fossil Acacia pollen in Australia are from the late Oligocene epoch, 25 million years ago.
They are present in all terrestrial habitats, including alpine settings, rainforests, woodlands, grasslands, coastal dunes and deserts. In drier woodlands or forest they are an important component of the understory. Elsewhere they may be dominant, as in the Brigalow Belt, Myall woodlands and the eremaean Mulga woodlands.
In Australia, Acacia forest is the second most common forest type after Eucalypt forest, covering 980,000 square kilometres (378,380 sq mi) or 8% of total forest area. Acacia is also the nation’s largest genus of flowering plants with almost 1,000 species found.
Several of its species bear vertically oriented phyllodes, which are green, broadened leaf petioles that function like leaf blades, an adaptation to hot climates and droughts. Some phyllodinous species have a colourful aril on the seed. A few species have cladodes rather than leaves.
Aboriginal Australians have traditionally harvested the seeds of some species, to be ground into flour and eaten as a paste or baked into a cake. The seeds contain as much as 25% more protein than common cereals, and they store well for long periods due to the hard seed coats. In addition to utilizing the edible seed and gum, the people employed the timber for implements, weapons, fuel and musical instruments. In ancient Egypt, an ointment made from the ground leaves of the plant was used to treat hemorrhoids. A number of species, most notably A. mangium (hickory wattle), A. mearnsii (black wattle) and A. saligna (coojong), are economically important and are widely planted globally for wood products, tannin, firewood and fodder. A. melanoxylon (blackwood) and A. aneura (mulga) supply some of the most attractive timbers in the genus. Black wattle bark supported the tanning industries of several countries, and may supply tannins for production of waterproof adhesives.
Acacia honey is not collected from plants in the acacia family, but rather from Robinia pseudoacacia, known as black locust in North America. Honey collected from Caragana arborescens is sometimes also called (yellow) acacia honey. See also Monofloral honey.
The hardened sap of various species of the acacia tree are known as acacia gum. Acacia gum is used as an emulsifier in food, a binder for watercolour painting, an additive to ceramic glazes, a binding in gum bichromate photography, a protective layer in the lithographic processes and as a binder to bind together fireworks.
Some species of acacia - notably A. baileyana, A. dealbata and A. pravissima - are cultivated as ornamental garden plants. The 1889 publication 'Useful native plants of Australia' describes various uses for eating.
Acacia (Ακακία) is a social fraternity founded in 1904 at the University of Michigan in Ann Arbor, Michigan. The fraternity has 28 active chapters and 4 colonies throughout Canada and the United States. The fraternity was founded by undergraduate Freemasons, and was originally open only to men who had taken the Masonic obligations, but in 1933 the International Conclave elected to dispense with the Masonic prerequisite. In 1988, at the 45th Conclave, the fraternity elected to use "International" rather than "National" when referring to the fraternity.Acacia Mining
Acacia Mining (formerly African Barrick Gold plc) is a gold mining business operating in Tanzania, with exploration properties in Kenya, Burkina Faso and Mali. It is listed on the London Stock Exchange and the Dar es Salaam Stock Exchange and is a constituent of the FTSE 250 Index. Acacia's majority shareholder is Barrick Gold, which owns 63.9% of the company.Acacia Ridge, Queensland
Acacia Ridge is a suburb of the City of Brisbane, Queensland, Australia. Acacia Ridge is 15 kilometres (9 mi) south of the central business district. It is within the local government area of City of Brisbane.Primarily residential, Acacia Ridge is also known for its heavy industrial area in the suburb's east, occupying much of the suburb's area east of Beaudesert Road. Acacia Ridge is home to one of Brisbane's few ice skating rinks.Acacia koa
Acacia koa is a species of flowering tree in the pea family, Fabaceae. It is endemic to the Hawaiian Islands, where it is the second most common tree. The highest populations are on Hawaiʻi, Maui and Oʻahu. Its name in the Hawaiian language, koa, also means brave, bold, fearless, or warrior.Acacia melanoxylon
Acacia melanoxylon, commonly known as the Australian blackwood, is an Acacia species native in South eastern Australia. The species is also known as Blackwood, hickory, mudgerabah, Tasmanian blackwood, or blackwood acacia.Acacia pycnantha
Acacia pycnantha, most commonly known as the golden wattle, is a tree of the family Fabaceae native to southeastern Australia. It grows to a height of 8 m (26 ft) and has phyllodes (flattened leaf stalks) instead of true leaves. Sickle-shaped, these are between 9 and 15 cm (3 1⁄2 and 6 in) long, and 1–3.5 cm (1⁄2–1 1⁄2 in) wide. The profuse fragrant, golden flowers appear in late winter and spring, followed by long seed pods. Plants are cross-pollinated by several species of honeyeater and thornbill, which visit nectaries on the phyllodes and brush against flowers, transferring pollen between them. An understorey plant in eucalyptus forest, it is found from southern New South Wales and the Australian Capital Territory, through Victoria and into southeastern South Australia.
Explorer Thomas Mitchell collected the type specimen, from which George Bentham wrote the species description in 1842. No subspecies are recognised. The bark of A. pycnantha produces more tannin than any other wattle species, resulting in its commercial cultivation for production of this compound. It has been widely grown as an ornamental garden plant and for cut flower production, but has become a weed in South Africa, Tanzania, Italy, Portugal, Sardinia, India, Indonesia, New Zealand, as well as Western Australia, Tasmania and New South Wales. Acacia pycnantha was made the official floral emblem of Australia in 1988, and has been featured on the country's postal stamps.Anadenanthera colubrina
Anadenanthera colubrina (also known as vilca, huilco, huilca, wilco, willka, curupay, curupau, cebil, or angico) is a South American tree closely related to yopo, or Anadenanthera peregrina. It grows to 5–20 m (16–66 ft) tall and the trunk is very thorny. The leaves are mimosa-like, up to 30 cm (12 in) in length and they fold up at night. In Argentina, A. colubrina produces flowers from September to December and bean pods from September to July. In Brazil A. colubrina has been given "high priority" conservation status.Anadenanthera peregrina
Anadenanthera peregrina, also known as yopo, jopo, cohoba, parica or calcium tree, is a perennial tree of the genus Anadenanthera native to the Caribbean and South America. It grows up to 20 m (66 ft) tall, and has a horny bark. Its flowers are pale yellow to white and spherical. It is an entheogen which has been used in healing ceremonies and rituals for thousands of years in South America.Fabaceae
The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, are a large and economically important family of flowering plants. It includes trees, shrubs, and perennial or annual herbaceous plants, which are easily recognized by their fruit (legume) and their compound, stipulate leaves. Many legumes have characteristic flowers and fruits. The family is widely distributed, and is the third-largest land plant family in terms of number of species, behind only the Orchidaceae and Asteraceae, with about 751 genera and about 19,000 known species. The five largest of the genera are Astragalus (over 3,000 species), Acacia (over 1000 species), Indigofera (around 700 species), Crotalaria (around 700 species), and Mimosa (around 400 species), which constitute about a quarter of all legume species. The ca. 19,000 known legume species amount to about 7% of flowering plant species. Fabaceae is the most common family found in tropical rainforests and in dry forests in the Americas and Africa.Recent molecular and morphological evidence supports the fact that the Fabaceae is a single monophyletic family. This conclusion has been supported not only by the degree of interrelation shown by different groups within the family compared with that found among the Leguminosae and their closest relations, but also by all the recent phylogenetic studies based on DNA sequences. These studies confirm that the Fabaceae are a monophyletic group that is closely related to the Polygalaceae, Surianaceae and Quillajaceae families and that they belong to the order Fabales.Along with the cereals, some fruits and tropical roots, a number of Leguminosae have been a staple human food for millennia and their use is closely related to human evolution.The Fabaceae family includes a number of important agricultural and food plants, including Glycine max (soybean), Phaseolus (beans), Pisum sativum (pea), Cicer arietinum (chickpeas), Medicago sativa (alfalfa), Arachis hypogaea (peanut), Ceratonia siliqua (carob), and Glycyrrhiza glabra (liquorice). A number of species are also weedy pests in different parts of the world, including: Cytisus scoparius (broom), Robinia pseudoacacia (black locust), Ulex europaeus (gorse), Pueraria lobata (kudzu), and a number of Lupinus species.Gum arabic
Gum arabic, also known as acacia gum, arabic gum, gum acacia, acacia, Senegal gum and Indian gum, and by other names, is a natural gum consisting of the hardened sap of various species of the acacia tree. Gum arabic is collected from acacia species, predominantly Acacia senegal and Vachellia (Acacia) seyal. The term "gum arabic" does not indicate a particular botanical source. In a few cases so‐called "gum arabic" may not even have been collected from Acacia species, but may originate from Combretum, Albizia or some other genus. The gum is harvested commercially from wild trees, mostly in Sudan (80%) and throughout the Sahel, from Senegal to Somalia—though it is historically cultivated in Arabia and West Asia.
Gum arabic is a complex mixture of glycoproteins and polysaccharides predominantly consisting of arabinose and galactose. It is soluble in water, edible, and used primarily in the food industry as a stabilizer, with EU E number E414. Gum arabic is a key ingredient in traditional lithography and is used in printing, paint production, glue, cosmetics and various industrial applications, including viscosity control in inks and in textile industries, though less expensive materials compete with it for many of these roles.
While gum arabic is now produced throughout the African Sahel, it is still harvested and used in the Middle East.List of Acacia species
Several cladistic analyses have shown that the genus Acacia is not monophyletic. While the subg. Acacia and subg. Phyllodinae are monophyletic, subg. Aculeiferum is not. This subgenus consists of three clades. Therefore, the following list of Acacia species cannot be maintained as a single entity, and must either be split up, or broadened to include species previously not in the genus. This genus has been provisionally divided into 5 genera, Acacia, Vachellia, Senegalia, Acaciella and Mariosousa. The proposed type species of Acacia is Acacia penninervis.Which of these segregate genera is to retain the name Acacia has been controversial. The genus was previously typified with the African species Acacia scorpioides (L.) W.F.Wright, a synonym of Acacia nilotica (L.) Delile. Under the original typification, the name Acacia would stay with the group of species currently recognized as the genus Vachellia. Orchard and Maslin proposed a retypification of the genus Acacia with the species Acacia penninervis Sieber ex DC., an Australian species that is a member of the largest clade within Acacia, a primarily Australian group formerly recognized as Acacia subgenus Phyllodinae, on the basis that this results in the fewest nomenclatural changes. Although this proposal met with strong disagreement by some authors, it was accepted on 16 July 2005 by the XVII International Botanical Congress in Vienna, Austria. Consequently, the name Acacia is conserved for 948 Australian species, 7 in the Pacific Islands, 1 or 2 in Madagascar and 10 in tropical Asia. Those outside Australia are split between the genera Acaciella, Mariosousa, Senegalia, and Vachellia. This decision was upheld at the 2011 Congress.In its new circumscription, the genus Acacia (now limited to the Australian species) has seven subgenera—Alatae (an artificial section), Botrycephalae, Juliflorae, Lycopodiifoliae, Plurinerves, Phyllodinae, and Pulchellae (see below). The other species, distributed in the Indian Ocean, tropical Asia and tropical America are now classified under
Vachellia (former subgenus Acacia): 163 species (pantropical)
Senegalia (former subgenus Aculeiferum): 203 species (pantropical)
Acaciella (former subgenus Aculeiferum section Filicinae): 15 species (Americas)
Mariosousa: 13 species related to (and including) Acacia coulteri (Americas)Two Australian acacias were re-classified under Vachellia, and another two under Senegalia.Mimosoideae
The Mimosoideae are trees, herbs, lianas, and shrubs that mostly grow in tropical and subtropical climates. They comprise a clade, previously placed at the subfamily or family level in the flowering plant family Fabaceae (Leguminosae). In previous classifications (e.g. the Cronquist system), Mimosoideae refers to what was formerly considered the tribe Mimoseae. Characteristics include flowers in radial symmetry with petals that are valvate (twice divided) in bud, and have numerous showy, prominent stamens. Mimosoideae comprise about 40 genera and 2,500 species.Phyllode
Phyllodes are modified petioles or leaf stems, which are leaf-like in appearance and function. In some plants, these become flattened and widened, while the leaf itself becomes reduced or vanishes altogether. Thus the phyllode comes to serve the purpose of the leaf.
They are common in the genus Acacia, especially the Australian species, at one time put in Acacia subg. Phyllodineae. Sometimes, especially on younger plants, partially formed phyllodes bearing reduced leaves can be seen. The illustration (to the right) of Acacia suaveolens from Novae Hollandiae plantarum specimen shows the juvenile true leaves, together with the developing phyllodes, and the phyllodes of the mature plant.
The genus, Daviesia, in the Fabaceae family, is characterised in part by the plants having phyllodes.
Phyllodes in FabaceaePrunus spinosa
Prunus spinosa, called blackthorn or sloe, is a species of flowering plant in the rose family Rosaceae. It is native to Europe, western Asia, and locally in northwest Africa. It is also locally naturalised in New Zealand, Tasmania and eastern North America.Robinia pseudoacacia
Robinia pseudoacacia, commonly known in its native territory as black locust, is a medium-sized hardwood deciduous tree endemic to a few small areas of the United States, but it has been widely planted and naturalized elsewhere in temperate North America, Europe, Southern Africa and Asia and is considered an invasive species in some areas. Another common name is false acacia, a literal translation of the specific name (pseudo meaning fake or false and acacia referring to the genus of plants with the same name.) It was introduced into Britain in 1636.Sahel
The Sahel () is the ecoclimatic and biogeographic zone of transition in Africa between the Sahara to the north and the Sudanian Savanna to the south. Having a semi-arid climate, it stretches across the south-central latitudes of Northern Africa between the Atlantic Ocean and the Red Sea. The name is derived from the Arabic word sāḥil (ساحل, Arabic pronunciation: [ˈsaːħil]) meaning "coast" or "shore" in a figurative sense (in reference to the southern edge of the vast Sahara), while the name in Swahili means "coastal [dweller]" in a literal sense.
The Sahel part of Africa includes (from west to east) parts of northern Senegal, southern Mauritania, central Mali, northern Burkina Faso, the extreme south of Algeria, Niger, the extreme north of Nigeria, central Chad, central and southern Sudan, the extreme north of South Sudan, Eritrea, Cameroon, Central African Republic and the extreme north of Ethiopia.Historically, the western part of the Sahel was sometimes known as the Sudan region. This belt was roughly located between the Sahara and the coastal areas of West Africa.The Acacia Strain
The Acacia Strain is an American metalcore band from Chicopee, Massachusetts. The group was formed in 2001 and has gone through several lineup changes; vocalist Vincent Bennett is the only current original member. Prior to his leaving guitarist Daniel "DL" Laskiewicz was the most recent original member to depart, remaining with The Acacia Strain until 2013.
The Acacia Strain is currently signed to Rise Records. In total, the group have released 7 full-length albums.USCGC Acacia (WLB-406)
The USCGC Acacia (WLB 406) was second to the last of a fleet of 39 similar 180-foot seagoing buoy tenders completed during World War II. Acacia was named after the former United States Lighthouse Service tender Acacia, the only tender sunk during World War II. Acacia is a multi-purpose vessel, nominally a buoy tender, but with equipment and capabilities for ice breaking, search and rescue, fire fighting, logistics, and other tasks as well.Acacia was homeported in Port Huron, Michigan, Sturgeon Bay, WI, Grand Haven, MI and Charlevoix, MI. The ship's primary duty was maintaining more than 210 buoys, lighthouses, and other navigational aids. Her area of operation ranged from as far south as Calumet Harbor, south Chicago, to as far north as Little Bay de Noc, including Green Bay, Wisconsin; Sturgeon Bay, Wisconsin; and Wisconsin’s Door Peninsula.Among her various duties were search and rescue of lost or disabled vessels and icebreaking assistance during the cold winter months. During the ice season, Acacia was one of several Coast Guard ice breakers engaged in Operation Coal Shovel, which keeps the channels between Toledo, Ohio and Detroit, Michigan open for the coal ships supplying power plants and industries in Detroit.Acacia also worked with NOAA in their efforts to acquire accurate weather information and with the United States Fish and Wildlife Service when they stocked Lake Michigan with hundreds of thousands of yearling trout.
Acacia was decommissioned June 7, 2006 after 62 years of service. Acacia was the second to last of the 180-foot (55 m) vessels to serve. Although another ship was not assigned to Acacia's last home port, her duties were picked up then by newly commissioned USCGC Mackinaw which is equipped to handle buoy tending as well as ice breaking.Vachellia nilotica
Vachellia nilotica (commonly known as gum arabic tree, babul, thorn mimosa, Egyptian acacia or thorny acacia) is a tree in the family Fabaceae. It is native to Africa, the Middle East and the Indian subcontinent. It is also a Weed of National Significance and is an invasive species of significant concern in Australia.