Acacia nilotica subsp nilotica

Invasive species Disclaimer

In view of the fact that some tree species are invasive, the world Agroforestry Center (ICRAF) has put in place a policy document on Invasive Alien Species, currently under draft available at Here.

For more information on this subject, please refer to
100 of the World's worst Invasive and Alien Species.




Species Index    A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Multiple Criteria Search


Abelmoschus moschatus
Acacia aneura
Acacia angustissima
Acacia aulacocarpa
Acacia auriculiformis
Acacia catechu
Acacia cincinnata
Acacia crassicarpa
Acacia elatior
Acacia erioloba
Acacia etbaica
Acacia ferruginea
Acacia glauca
Acacia holosericea
Acacia karroo*
Acacia koa
Acacia laeta
Acacia lahai
Acacia leptocarpa
Acacia leucophloea
Acacia mangium
Acacia mearnsii*
Acacia melanoxylon
Acacia mellifera
Acacia nilotica subsp nilotica
Acacia pachycarpa
Acacia pennatula
Acacia polyacantha ssp. polyacantha
Acacia saligna
Acacia senegal
Acacia seyal
Acacia sieberiana
Acacia tortilis
Acacia xanthophloea
Acrocarpus fraxinifolius
Adansonia digitata
Adenanthera pavonina
Aegle marmelos
Afzelia africana
Afzelia quanzensis
Agathis macrophylla
Agathis philippinensis
Ailanthus altissima
Ailanthus excelsa
Ailanthus triphysa
Albizia adianthifolia
Albizia amara
Albizia anthelmintica
Albizia chinensis
Albizia coriaria
Albizia ferruginea
Albizia gummifera
Albizia julibrissin
Albizia lebbeck
Albizia odoratissima
Albizia procera
Albizia saman
Albizia versicolor
Albizia zygia
Aleurites moluccana
Allanblackia floribunda
Allanblackia stuhlmannii
Allanblackia ulugurensis
Alnus acuminata
Alnus cordata
Alnus japonica
Alnus nepalensis
Alnus rubra
Alphitonia zizyphoides
Alstonia boonei
Alstonia congensis
Alstonia scholaris
Altingia excelsa
Anacardium occidentale
Andira inermis
Annona cherimola
Annona muricata
Annona reticulata
Annona senegalensis
Annona squamosa
Anogeissus latifolia
Anthocephalus cadamba
Antiaris toxicaria
Antidesma bunius
Araucaria bidwillii
Araucaria cunninghamii
Arbutus unedo
Areca catechu
Arenga pinnata
Argania spinosa
Artemisia annua
Artocarpus altilis
Artocarpus camansi
Artocarpus heterophyllus
Artocarpus integer
Artocarpus lakoocha
Artocarpus mariannensis
Asimina triloba
Ateleia herbert-smithii
Aucomea klaineana
Averrhoa bilimbi
Averrhoa carambola
Azadirachta excelsa
Azadirachta indica
Azanza garckeana
Related Links
A. nilotica is one of the most widely planted and used trees in northern India for tannin from bark (foreground), firewood (middle) and charcoal(background), as here in the Punjab.
© Colin E. Hughes
Typical tree of A. nilotica, being lopped for livestock fodder in Rajasthan, India.
© Colin E. Hughes
A. nilotica var cupressiformis, valued for its fastigiate branching and narrow columnar crown suggesting unusual agroforestry potential, here in trials at the Central Arid Zone Research Institute, Rajasthan, India.
© Colin E. Hughes
A. nilotica, tree on Santiago, Cape Verde Islands.
© David Boshier
A. nilotica, tree on Santiago, Cape Verde Islands.
© David Boshier
A. nilotica, stand of trees, Santiago, Cape Verde Islands.
© David Boshier
A. nilotica, flowers.
© David Boshier
Acacia nilotica pods.
© Chris Gardiner
Acacia nilotica pods.
© Chris Gardiner
Flowers and spines
© Anthony Simons
Flowering A. nilotica subsp. leiocarpa: The rounded crown of subsp. leiocarpa is beginning to bloom on the coast of Kenya.
© Chris Fagg
Plantation of A. nilotica subsp. tomentosa: A. nilotica subsp. tomentosa stand planted on a 30 year rotation for timber on the Blue Nile floodplain near Dinder, Sudan.
© Chris Fagg
Young bush: A young bush of A. nilotica subsp. adstringens in Burkina Faso.
© Chris Fagg
Flowers of A. nilotica subsp. adstringens: Flowers of A. nilotica are arranged in bright yellow orange globose inflorescences, such as this shoot (growing in Burkina Faso).
© Chris Fagg
Pods: Green indehiscent pods of A. nilotica ssp. leiocarpa which turn black when mature, Kenya.
© Chris Fagg
Avenue planting in India: A. nilotica subsp. indica planted as an avenue tree
© Chris Fagg
Windbreak: A. nilotica subsp. cupressiformis planted along field boundaries as windbreaks in Pali, Rajasthan, India.
© Colin Hughes

Acacia nilotica ssp. nilotica is an evergreen, usually moderate-sized (2.5-25 m) tree with a short, thick and cylindrical trunk; bark is grey, reddish-brown or black, rough, furrowed.

Leaves are alternate, bipinately compound, 5-15 cm long; axis fairly hairy, with 3-8 pairs of side axes (pinnae) 1-4 cm long; leaflets 10-30 pairs on each side axis, small, narrowly oblong, 3-6 mm long, blunt at the ends with tiny hairs along edges, grey-green.

Flowers many, crowded, stalkless, 6-8 mm long, composed of 5-toothed corolla 3 mm long; many yellow, threadlike stamens, 6 mm long, united at base, with yellow, dotlike anthers and pistil with slender ovary and threadlike style.

Pods long, narrow, flattened, 8-17 x 1-2 cm, straight, mostly narrowed between seeds, stalked at the base, short, pointed grey or black, mostly aromatic, not splitting open, breaking in segments; seeds 8-15, beanlike, 7-9 mm in diameter, rounded, flattened, blackish-brown.

It has considerable variation with nine subspecies presently recognized, three occurring in the Indian subcontinent and six throughout Africa. They are distinguished by the shape and pubescense of pods and the habit of the tree. The species is similar to other A. nilotica subspecies, but is distinguished by its glabrous fruits. The generic name ‘acacia’ comes from the Greek word ‘akis’, meaning a point or a barb. The typical A. nilotica is native to the Nile countries, hence the specific name.

Ecology

A. nilotica ssp. nilotica has a strong light requirement. Severe frost affects small seedlings as well as large trees. It is drought resistant and occurs in plain, flat or gently undulating ground and ravines. Trees grow best on alluvial soils in ravine areas subject to periodic inundation. It is considered a serious weed in South Africa. The tree is widespread in the northern savannah regions, and its range extends from Mali to Sudan and Egypt.

Native range
Botswana, Egypt, Eritrea, Ethiopia, India, Kenya, Mozambique, Namibia, Nigeria, Oman, Pakistan, Saudi Arabia, Sudan, Swaziland, Tanzania, Uganda, Yemen, Republic of, Zambia, Zimbabwe

Tree management

Young seedlings are said to require full sun and frequent weeding. A. nilotica ssp. nilotica coppices very weakly.

Seed storage behaviour is orthodox. Viability can be maintained for several years in airtight, moisture-proof conditions at 10 deg. C. with 4.5-9% mc. There are 5000-10 000 seeds/kg.

A. nilotica ssp. nilotica has a strong light requirement. Severe frost affects small seedlings as well as large trees. It is drought resistant and occurs in plain, flat or gently undulating ground and ravines. Trees grow best on alluvial soils in ravine areas subject to periodic inundation. It is considered a serious weed in South Africa. The tree is widespread in the northern savannah regions, and its range extends from Mali to Sudan and Egypt.

Direct seeding is commonly used to propagate the tree, though potted seedlings may also be used. Pretreatment involves boiling seed in water followed by cooling or immersion in concentrated sulphuric acid for 1 hour. Germination rates of 75-95% can be realized in 1 week. Bare-root seedlings are seldom used because the high incidence of root injury causes poor survival rates.

Poison:  The aqueous extract of the fruit, rich in tannin (18-23%), has shown algicidal activity against Chroccoccus, Closteruim, Coelastrum, Cosmarium, Cyclotella, Euglena, Microcystis, Oscillatoria, Pediastrum, Rivularia, Spirogyra and Spirulina.

In India, this species is used on degraded saline and alkaline soils. It grows well when irrigated with tannery effluent and colonizes coal mine waste heaps. Over 50 % of the Chambal ravines in India have been revegetated with A. n. ssp. nilotica.

  Tender pods and shoots are used as a vegetable, and roasted seed kernels are sometimes used in Sudan for food flavouring. Air-dried seeds contain crude protein and are eaten raw or roasted in India in time of acute food scarcity.

The crude protein content of the leaves is 14-20%, and 11-16 % for the highly palatable pods. Pods and shoots are used as forage for camels, sheep and goats, especially in Sudan, where it is said to improve milk from these animals. In India, it constitutes a chief diet for goats and sheep, and seeds are a valuable cattle food.

Apiculture: The fragrant flowers of A. nilotica ssp. nilotica are popular bee forage.

The calorific value of the sapwood is 4500 kcal/kg, while that of the heartwood is 4950 kcal/kg. This valuable source of firewood and charcoal has been used in locomotives, river steamers and small industries. Burning charcoal, however, emits sparks. In India and Pakistan riverine plantations are managed on a 15-20 year rotation for fuel wood and timber.

Fibre:  Young bark is used as fibre.

Timber: Since the time of the Pharoahs, large timber trees have been exploited from the riverine forests of the Nile. Sapwood is yellowish-white and heartwood reddish-brown, hard, heavy, durable, difficult to work, although it takes a high polish. Because of its resins, it resists insects and water, and it is harvested for boat making, posts, buildings, water pipes, well planking, ploughs, cabinet work, wheels, tool handles, carts, mallets and other implements. It is an attractive wood, good for carving and turnery. It is the best mining timber in Pakistan. Sudan forests have been managed on a 20-30 year rotation producing termite resistant timber especially suitable for railway sleepers.

Tannin or dyestuff: The pods of ssp. nilotica have been used for tanning in Egypt for over 6 000 years. The inner bark contains 18-23% tannin, which is used for tanning and dyeing leather black. Young pods produce a very pale tint in leather, notably goat hides. Extracts from the bark, leaves and pods are used for dyeing cotton, silk and leather. Roasted seed kernels, when crushed, provide a dye for the black strings worn by Nankani women of Sudan.

Medicine:  The Zulu of South Africa take the bark for cough. The Maasai of East Africa use a bark decoction as a nerve stimulant, and the root is said to cure impotence. An astringent from the bark is used for diarrhoea, dysentery and leprosy. Bruised leaves are poulticed onto ulcers. The gum or bark is used for cancers and tumours of the ear, eye or testicles and indurations of the liver and spleen, condylomas and excess flesh. Other ailments treated by these products include colds, congestion, fever, gallbladder, haemorrhage, haemorrhoids, leucorrhoea, ophthalmia, sclerosis and smallpox. Bark, gum, leaves and pods are used medicinally in West Africa. Sap or bark, leaves and young pods are strongly astringent because of the tannin the possess, and in Senegal are chewed as an antiscorbutic, and in Ethiopia as a lactogogue. A bark decoction is drunk for intestinal pains. Other preparations are used for, gargle, toothache, ophthalmia and syphilitic ulcers. In Tonga, the root is used to treat tuberculosis. In Lebanon, the resin is mixed with an orange-flower infusion for typhoid convalescence. In Somalia, the wood is used to treat smallpox. Egyptian Nubians believe that diabetics may eat unlimited carbohydrates without any consequences as long as they also consume the pods in powder form. Extracts are inhibitory to at least 4 species of pathogenic fungi.

Gum or resin:  A. nilotica ssp. nilotica is probably the earliest source of gum arabic, although this now comes mainly from A. senegal. The gum tapped from the bark is used in manufacturing matches, inks, paints and confectionery.

This subspecies makes an ideal windbreak surrounding fields; its narrow crown shades less than other windbreak species.

Soil improver:  Probably nitrogen fixing.

Intercropping:  When intercropped with A. nilotica ssp. nilotica in semi-arid Nigeria, sorghum showed heavily depressed yields.