| Andropogon gayanus | |
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Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Clade: | Commelinids |
| Order: | Poales |
| Family: | Poaceae |
| Subfamily: | Panicoideae |
| Genus: | Andropogon |
| Species: | A. gayanus |
| Binomial name | |
| Andropogon gayanus | |
Andropogon gayanus. commonly known as gamba grass, Rhodesian blue grass, tambuki grass, and other names, is a species of grass native to most of the tropical and subtropical savannas of Africa.
Andropogon gayanus was recognised and named by 1833. [1] Its common names include gamba grass, bluestem (Africa, Australia); Rhodesian andropogon (southern Africa); Rhodesian blue grass (Zimbabwe); onga, tambuki grass (north-west Africa); and sadabahar (India). [2]
This tufting perennial bunchgrass can grow 4 m (13 ft) tall and 70 cm (2.3 ft) in diameter, and has hairy leaves. Most of its roots are fibrous, [2] spreading close to the surface of the soil for up to 1 m (3 ft 3 in), [3] but it also has thick cord roots which store starch and anchor the plant as well as vertical roots able to extract water from a greater depth during the dry season. [2]
It produces large numbers of light, fluffy seeds (up to 244,000 seeds each year, with 65% viability [3] ), which can be spread by wind, animals or machinery. [2] It spreads rapidly where vegetation is disturbed, but most seeds fall within 5 m (16 ft) of the parent plant. [3]
The grass is native to most of the tropical and subtropical savannas of Africa, [4] also extending southwards into Mozambique, Botswana, Namibia and South Africa in regions with long dry seasons. It occurs naturally in xerophytic grasslands on doleritic, sandy or clay soils, at altitudes of up to 1,500 m (4,900 ft), and is very drought-tolerant. However it does not do well where mean minimum temperatures dip below 4.4 degrees Celsius, and it is not frost-tolerant. [2]
However, it has been introduced to many parts of the world, including tropical countries of the Americas, and has naturalised in Brazil [2] and other countries. It was mainly introduced for use as an improved pasture plant. [3]
Gamba grass was introduced into the Northern Territory of Australia in 1931 for trial as cattle feed, [5] and was imported into the state of Queensland as a pasture grass in 1942, but was not planted on a large scale until about 1983. Almost all known locations in Queensland are in areas below 980 m (3,220 ft) altitude that receive 400–1,500 mm (16–59 in) annual rainfall. [3]
A. gayanus is used as a pasture crop for cattle in many countries, [2] including in far north Queensland in Australia. [3] and has been used in Nigeria to reclaim land that has been overgrazed. [2]
Strips of the grass planted in millet fields help to reduce wind erosion of the soil. [2]
In some African countries, the stems are used as thatch. [2] and for making pen.
It has been declared a noxious species, officially a "Weed of national significance" in Australia since 2012, [6] [2] [5] where it forms dense patches, out-competing native species and altering ecosystems. Areas of dense infestation have a significantly higher fire risk than native pastures. [7] [8] It is highly resistant to both cutting and fire, and ungrazed tussocks can generate very intense fires, [2] leading to loss of tree cover and long-term environmental damage. It replaces native grasses, reducing natural biodiversity on ungrazed land. Being highly invasive, it can move into conservation areas, semi-urban residential land and mining leases. [3]
In the NT, where there are large swathes of the plant between Darwin, Northern Territory and Katherine, conservationist Mitch Hart described gamba grass as a "triple threat": to people's lives, to the economy of Territory, and the potential destruction of Australia's northern savanna, [5]
WA, NT and Queensland have state legislation which prohibits planting of new plants, and compels land managers to control infestations. [6]
David Bowman, a professor of environmental change biology at the University of Tasmania suggested in 2013 that the introduction of African elephants to Australia could be considered to control the gamba grass, as a rewilding trial. [9]
The state of Western Australia, where infestations have not been as widespread as the NT and Queensland, established the Gamba Grass Eradication Program, a collaborative project supported by the Department of Biodiversity, Conservation and Attractions, the Department of Primary Industries and Regional Development, El Questro Station and Kimberley Rangelands Biosecurity Association. The control program, started in 2011, has been highly successful, reducing the numbers of plants to 3,000 by 2018, and just 23 by 2020. They found only eight plants in the 2021 wet season. However it receives no funding from the federal government, and monitoring is necessary for a further five years to ensure that it does not spread again. [5]
A savanna or savannah is a mixed woodland-grassland ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. According to Britannica, there exists four savanna forms; savanna woodland where trees and shrubs form a light canopy, tree savanna with scattered trees and shrubs, shrub savanna with distributed shrubs, and grass savanna where trees and shrubs are mostly nonexistent.
Cryptostegia grandiflora, commonly known as rubber vine, is a woody-perennial vine that is native to south-west Madagascar. It is also a significant weed in northern Australia, sometimes regarded as the worst weed in all of Australia. It has also been introduced to most other tropical and subtropical regions by man, because of its attractive flowers and the fact that its latex contains commercial quality rubber. It is now naturalised in the Caribbean, East Africa, Mauritius, India, Southeast Asia, Indonesia, Latin America, the southern United States, Fiji and New Caledonia. It is very similar to the purple rubber vine, which is also native to Madagascar.
Cenchrus ciliaris is a species of grass native to most of Africa, southern Asia, southern Iran, and the extreme south of Europe (Sicily). Other names by which this grass is known include dhaman grass, anjan grass, koluk katai and buffelgrass.
Cenchrus is a widespread genus of plants in the grass family. Its species are native to many countries in Asia, Africa, Australia, the Americas, and various oceanic islands.
The Barkly Tableland is a region in the Central East if the Northern Territory, extending into Western Queensland. The region was named after Sir Henry Barkly. The epithet “Tableland” is inaccurate, since the region is neither elevated relative to adjacent landforms, nor are the boundaries marked by a distinct change in elevation
Miconia crenata, commonly called soapbush, clidemia or Koster's curse, is a perennial shrub. It is an invasive plant species in many tropical regions of the world, creating serious damage.
Myriogenospora aciculispora is a fungal plant pathogen. It has been reported to cause disease among sugarcane in Brazil.
The Northern Territory (NT) occupies the north central part of the continent of Australia. The Northern Territory borders are to the west with Western Australia, the Western Australia border being near the 129° east longitude. The NT to the south with the South Australian border being the 26th parallel south latitude. To the east the NT with the Queensland border along the 138° east longitude.
Macroptilium atropurpureum, commonly referred to as purple bush-bean, or siratro is a perennial legume recognized by its climbing, dense, green vines and deep purple flowers. The plant is indigenous to the tropical and subtropical regions of North, Central, and South America, as far north as Texas in the USA and as far south as Peru and Brazil. It has been introduced for use as a food for stock to many tropical regions around the world. It has become an invasive pest plant in a number of areas, including the north-eastern coast of Australia. Rich in protein, M. atropurpureum is commonly used for cattle pastures intercropped with grass, used in hay, or as a ground cover to prevent soil erosion and to improve soil quality.
Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perennial plants, most species live more than one season. Tussock grasses are often found as forage in pastures and ornamental grasses in gardens.
Chrysopogon is a genus of tropical and subtropical plants in the grass family. They are widespread across Eurasia, Africa, Australia, southeastern North America, and various islands.
Megathyrsus maximus, known as Guinea grass and green panic grass, is a large perennial bunch grass that is native to Africa and Yemen. It has been introduced in the tropics around the world. It has previously been called Urochloa maxima and Panicum maximum. It was moved to the genus Megathyrsus in 2003.
Bothriochloa bladhii is a Neotropic grass in the family Poaceae, found primarily in tropical Africa, and tropical and temperate Asia, and Australia. The type specimen was collected from China by Finnish botanist Peter Johan Bladh. The name of Bladh is honored in the specific epithet.
Bela "Bert" Grof was a Hungarian-born Australian agricultural researcher with contributions to grassland and forage research in the tropics.
Themeda quadrivalvis is a species of grass known by the common names grader grass, habana grass, and kangaroo grass, not to be confused with Themeda triandra, which is also known as kangaroo grass. It is native to India, Nepal, and Malaysia. It can also be found in many other places as an introduced species and often a noxious weed. It occurs in the United States, New Caledonia, Fiji, Mauritius, Thailand, Indonesia, Papua New Guinea, China, the Middle East and tropical America. It is a troublesome exotic weed in Australia, especially in northern regions. It is also an agricultural weed in crops such as sugar cane and lucerne.
In Australia, Mimosa pigra has been declared a noxious weed or given similar status under various weed or quarantine Acts. It has been ranked as the tenth most problematic weed and is listed on the Weeds of National Significance. It is currently restricted to the Northern Territory where it infests approximately 80,000 hectares of coastal floodplain.
Derrick Thomas was a British agricultural researcher with special contributions to grassland and forage research in the tropics.
Brachiaria mutica is a species of grass known by the common names para grass, buffalo grass, Mauritius signal grass, pasto pare, malojilla, gramalote, parana, Carib grass, and Scotch grass. Despite its common name California grass, it does not occur in California; it is native to northern and central Africa and parts of the Middle East, where it is cultivated for fodder. It was introduced elsewhere and it is now cultivated throughout tropical regions of the world for this purpose.
Hymenachne amplexicaulis, also known as West Indian marsh grass in the US, Olive hymenachne in Australia, and hereafter referred to as hymenachne, is New World species in the genus Hymenachne. Hymenachne is from the Greek hymen meaning "membrane" and achne meaning "chaff, glume, scale" and amplexicaulis is from Latin, literally "embracing the stem" or "stem-clasping. This freshwater species is native to the tropical and subtropical regions of the West Indies, Northern South America, and Central America.
Paspalum conjugatum, commonly known as carabao grass or hilo grass, is a tropical to subtropical perennial grass. It is originally from the American tropics, but has been naturalized widely in tropical Southeast Asia and Pacific Islands. It has also spread to Northern Africa and Northern and Eastern Australia. It is also known as sour paspalum, T-grass, or more confusingly, as "buffalo grass" or "sour grass".
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| Authority control databases: National |
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