Cookies on Invasive Species Compendium

Like most websites we use cookies. This is to ensure that we give you the best experience possible.

Continuing to use www.cabi.org means you agree to our use of cookies. If you would like to, you can learn more about the cookies we use.

Datasheet

Acacia hockii

Summary

  • Last modified
  • 22 November 2017
  • Datasheet Type(s)
  • Invasive Species
  • Preferred Scientific Name
  • Acacia hockii
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Plantae
  •     Phylum: Spermatophyta
  •       Subphylum: Angiospermae
  •         Class: Dicotyledonae
  • Summary of Invasiveness
  • A. hockii is a widespread acacia shrub or small tree found in moist savannah landscapes of sub-Saharan Africa. In East Africa particularly, it is one of the most common small Acacia species, and was no...

  • There are no pictures available for this datasheet

    If you can supply pictures for this datasheet please contact:

    Compendia
    CAB International
    Wallingford
    Oxfordshire
    OX10 8DE
    UK
    compend@cabi.org
  • Distribution map More information

Don't need the entire report?

Generate a print friendly version containing only the sections you need.

Generate report

Identity

Top of page

Preferred Scientific Name

  • Acacia hockii De Wild.

Other Scientific Names

  • Acacia chariensis A. Chev.
  • Acacia orfota sensu Brenan
  • Acacia seyal Delile var. multijuga Baker f.
  • Acacia seyal var. kassonionga De Wild.
  • Acacia seyal var. lescrauwaetii De Wild.
  • Acacia seyal var. seretii De Wild.
  • Acacia stenocarpa sensu auct.
  • Vachellia hockii (De Wild.) Seigler & Ebinger

International Common Names

  • English: white thorn acacia

Local Common Names

  • Burkina Faso: gar sabalaga
  • Congo Democratic Republic: kassonionga
  • Ethiopia: cholach; churach; churai; dak'ali
  • Kenya: arumbe; arumbe; burgupet; chepnyaliliet; chooh; chuwan; dabaso; echekereng; ekisim; ekkisisia; enchapalani; encharpalani; igisurua; kasaana; katet; kidenya; kinyua; kithi; kumunyenya; kuthe; lendet; luaa; mgunga; mugaa; munga; munyua; muoli; oiladili; olderbalan; olera; olerai; ol-jarbolani; orcharpalani; oriang; orjorai; telatibilit; tilatil
  • Nigeria: siludi
  • Rwanda: umugenge
  • Sudan: asorai; rariya; riangan; talh ahmar
  • Tanzania: ghaham; ilula; kasemele; kasemere; kisukula; kisusura; kusemele; mgunga; mnenyera; msese; msomdodu; mubanguti; mukengessa; munga; mzonapoli; sese
  • Uganda: kasana; kasoni; omugando
  • Zambia: chibombo; katete; munga; mupangala; uzimwe

EPPO code

  • ACAHO (Acacia hockii)

Summary of Invasiveness

Top of page

A. hockii is a widespread acacia shrub or small tree found in moist savannah landscapes of sub-Saharan Africa. In East Africa particularly, it is one of the most common small Acacia species, and was noted as invasive in parts of Uganda more than 50 years ago. It appears to be a typical ‘native invader’, increasing in plant density dramatically following certain changes to land management such as altering the fire regime or grazing system and/or changing climates. There are no records of intentional or accidental introduction of A. hockii to other countries, though there is a risk of invasion in other parts of its native range. Chemical control was shown to be effective but uneconomic, and cultural techniques may prove to be more cost effective.

Taxonomic Tree

Top of page
  • Domain: Eukaryota
  •     Kingdom: Plantae
  •         Phylum: Spermatophyta
  •             Subphylum: Angiospermae
  •                 Class: Dicotyledonae
  •                     Order: Fabales
  •                         Family: Fabaceae
  •                             Subfamily: Mimosoideae
  •                                 Genus: Acacia
  •                                     Species: Acacia hockii

Notes on Taxonomy and Nomenclature

Top of page

Although there have been some taxonomical issues regarding A. hockii in the past, it appears that its limits are now generally accepted. However, it is still incorrectly included as a synonym of the morphologically similar A. seyal Del. in some publications and databases (such as FAO, 2013 and ICRAF, 2013), and that continues to cause confusion. Although the two are closely related, it seems preferable to maintain them as distinct species.

In their monograph on A. seyal, Hall and McAllan (1993) stated that the then current view of A. seyal was essentially consistent with that put forward by Hutchinson and Dalziel (1958), when it was indicated for the first time that both A. seyal and A. hockii were widespread in tropical Africa. Hall and McAllan (1993) added that as distinctions between A. seyal and A. hockii became better appreciated, varieties originally described under the name A. seyal were adopted as synonyms of A. hockii.

A treatment of African Acacia species by Vassal (1972) placed A. hockii as one of 18 species in subsection Uniseriae, and in a subgroup of ten species with dehiscent pods and capitate inflorescences, also including A. ehrenbergiana, A. karroo, A. kirkii. A. macrothyrsa and A. xanthophloea

Vachellia hockii is also treated as a synonym here, being part of the reclassification of the entire Acacia genus that is proposed by some taxonomists but not universally accepted, though it has been adopted by some databases (such as USDA-ARS, 2013). The type specimen is from Katanga, DR Congo. Further taxonomic revision may be expected.

Description

Top of page

A. hockii is a multi-stemmed shrub 2-4 m tall, or a small tree to 6-7 m tall with an open crown occasionally 9 m wide, with 12 m also recorded in exceptional individuals. Bark is red-brown to greenish or greenish-brown, rarely pale-yellow, peeling off in papery layers, brown when not burned or grey brown and in plates where burned, yellow underneath. Inner bark is not powdery (as it is in A. seyal). Young twigs and branchlets puberulous to densely puberulous, rarely glabrous, with sessile glands, reddish, sometimes numerous, usually elongate and slender. The thorns are spinescent stipules, short (up to 2 cm long, rarely 4 cm), straight, suberect or spreading, subulate or flattened on the upper side, with ‘ant-galls’ and other prickles absent. Leaves have (1)2-11 pairs of pinnae; each with 9-29 pairs of leaflets, 2.0-6.5 mm long and 0.5-1.2 mm wide, usually densely ciliolate but sometimes glabrous, obtuse to acute but not spinulose-mucronate at the apex, with lateral nerves invisible beneath. Leaves often have a gland on the petiole and between the top 1(3) pairs of pinnae. Flowers are bright yellow or orange, in axillary, pedunculate heads 5-12 mm in diameter. The pods are reddish brown, narrow, straight or crescent shaped, puberulous and (4)5-14 cm long and 0.3-0.8 cm broad. Seeds are olive-brown, 5-7 x 3-4 mm, smooth, elliptic and compressed.

Plant Type

Top of page Broadleaved
Perennial
Seed propagated
Shrub
Tree
Woody

Distribution

Top of page

A. hockii is native to many dry areas in tropical Africa south of the Sahel, to eastern and southern Africa, and also Yemen (ILDIS, 2013). It is present in Saudi Arabia (GBIF, 2013) and likely to be native there also. In West Africa it occurs in the moister savannah regions of the Guinea zone. There are no records of intentional or accidental introduction of A. hockii to other countries.

Distribution Table

Top of page

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

Saudi ArabiaPresentNativeGBIF, 2012
YemenPresentNativeILDIS, 2013

Africa

AngolaPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
BeninPresentNativeILDIS, 2013
Burkina FasoPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
BurundiPresentNativeMissouri Botanical Garden, 2013
CameroonPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
Central African RepublicPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
ChadPresentNativeILDIS, 2013
Congo Democratic RepublicPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
Côte d'IvoirePresentNativeILDIS, 2013
EritreaPresentNativeGBIF, 2012
EthiopiaPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
GhanaLocalisedNativeILDIS, 2013; Missouri Botanical Garden, 2013Only in the north
GuineaPresentNativeILDIS, 2013
KenyaWidespreadNativeILDIS, 2013; Missouri Botanical Garden, 2013
MalawiPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
MaliPresentNativeILDIS, 2013
MozambiquePresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
NigerPresentNativeBurkill, 1995
NigeriaPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
RwandaPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
SudanPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
TanzaniaPresent only in captivity/cultivationNativeILDIS, 2013; Missouri Botanical Garden, 2013
TogoPresentNativeILDIS, 2013
UgandaPresentNative Invasive ILDIS, 2013; Missouri Botanical Garden, 2013Invasive, especially around Lake Mburo
ZambiaPresentNativeILDIS, 2013; Missouri Botanical Garden, 2013
ZimbabwePresentNativeILDIS, 2013

History of Introduction and Spread

Top of page

A. hockii is not a new invader. Harrington (1968) noted that it was the most widespread small Acacia species in East Africa, and 45 years ago it already occupied 77,700 square kilometres (30,000 square miles) of potentially high quality rangeland in Uganda. It has proved particularly invasive in south-western Uganda. In the Lake Mburo National Park, Mbarara District, NARO (2004) observed that A. hockii had become a major problem since the mid-1990s. In East Africa, it tends to invade overgrazed grasslands and evergreen thickets along with other species, including A. drepanolobium, A. kirkii and A. seyal.

Risk of Introduction

Top of page

Intentional introduction of A. hockii appears unlikely, as it is rarely found on lists of useful plants and is not identified as a plant for reforestation purposes, as are many other Acacia species. It is, however, listed by Parker et al. (2007) as a weed with the potential to invade the USA, and its introduction is prohibited in Australia.

Habitat

Top of page

A. hockii occupies a wide range both of habitat and altitude, from sea level to at least 2,400 m altitude. In West Africa, A. hockii is found in moister savannah regions of the Guinea zone. In East Africa it is found in deciduous woodland, wooded grassland and deciduous and semi-evergreen bushland, thickets and scrub. It can become common on sloping or rocky ground, and is often associated with poor soils, especially sandy soils, where it often becomes the dominant shrub.

Habitat List

Top of page
CategoryHabitatPresenceStatus
Terrestrial-managed
Cultivated / agricultural land Secondary/tolerated habitat Harmful (pest or invasive)
Managed grasslands (grazing systems) Secondary/tolerated habitat Harmful (pest or invasive)
Managed grasslands (grazing systems) Secondary/tolerated habitat Natural
Terrestrial-natural/semi-natural
Arid regions Principal habitat Harmful (pest or invasive)
Arid regions Principal habitat Natural
Natural grasslands Principal habitat Harmful (pest or invasive)
Natural grasslands Principal habitat Natural
Scrub / shrublands Secondary/tolerated habitat Harmful (pest or invasive)
Scrub / shrublands Secondary/tolerated habitat Natural

Biology and Ecology

Top of page

There is little specific information available in the literature regarding the biology of A. hockii, though it may be considered similar to that of the closely related A. seyal (see Hall and McAllan, 1993). A. hockii can withstand intensive browsing and is particularly fire tolerant, and tends to resprout vigorously after cutting or burning. Harker (1959) includes a description of A. hockii growth and development, and the effects of heat on seed germination.

Genetics

Different chromosome numbers have been reported, with Hamant et al. (1975) suggesting 2n=52, whereas Renaud et al. (1983) indicated that it was 2n=26. However, as with other African Acacia species, it is possible that more than one ploidy level exists in A. hockii.

Associations

A. hockii is a principal component of several plant associations. In Ethiopia, Heteropogon contortus-Acacia hockii was one of seven plant community types identified in Gamo Gofa Zone in the south (Soromessa et al., 2004), and Tikssa et al. (2010) noted Tamarix nilotica-Acacia hockii as one of the seven community types identified in the Awash valley. In Tanzania, A. hockii is common in Brachystegia woodland. In the Serengeti it can be one of the dominant species in Acacia-Commiphora wooded grassland and in the open understory in Combretum-Terminalia secondary wooded grassland. In the Maruzi Hills Forest Reserve in Uganda, species with the highest proportional abundance were Combretum molle (23%), A. hockii (17.7%), Combretum collinum (16.1%), Grewia mollis (6.5%) and Lannea barteri (6.5%).

In East Africa A. hockii tends to invade overgrazed grasslands and evergreen thickets along with other species, including A. drepanolobium, A. kirkii and A. seyal.

Environmental Requirements

A. hockii is a tropical species, preferring moist savannah regions, and so is generally absent in the true Sahelian zone and other drier savannahs where other Acacia species generally dominate. It can tolerate very high temperatures but is intolerant of frost. It also tolerates poor soils.

Climate

Top of page
ClimateStatusDescriptionRemark
As - Tropical savanna climate with dry summer Tolerated < 60mm precipitation driest month (in summer) and < (100 - [total annual precipitation{mm}/25])
Aw - Tropical wet and dry savanna climate Tolerated < 60mm precipitation driest month (in winter) and < (100 - [total annual precipitation{mm}/25])
B - Dry (arid and semi-arid) Preferred < 860mm precipitation annually
BS - Steppe climate Preferred > 430mm and < 860mm annual precipitation
BW - Desert climate Preferred < 430mm annual precipitation
Cs - Warm temperate climate with dry summer Tolerated Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers

Rainfall

Top of page
ParameterLower limitUpper limitDescription
Dry season duration48number of consecutive months with <40 mm rainfall
Mean annual rainfall2002000mm; lower/upper limits

Soil Tolerances

Top of page

Soil drainage

  • free
  • impeded

Soil reaction

  • acid
  • alkaline
  • neutral

Soil texture

  • heavy
  • light
  • medium

Special soil tolerances

  • infertile
  • saline
  • shallow
  • sodic

Means of Movement and Dispersal

Top of page

Natural Dispersal

Pods and seeds form part of the diet of native species and livestock (Gwyne, 1969), and elephants, antelope and chimpanzees seek out the dry pods (Wickens et al., 1995). Seed dispersal is likely to be aided by these animals. Seeds might also be dispersed by water where plants exists in areas liable to flooding.

Intentional Introduction

Intentional introduction of A. hockii appears unlikely, as it is rarely found on lists of useful plants and is not identified as a plant for reforestation purposes, as are many other Acacia species.

Pathway Vectors

Top of page
VectorNotesLong DistanceLocalReferences
Livestock Yes Gwyne, 1969

Impact Summary

Top of page
CategoryImpact
Economic/livelihood Positive and negative
Environment (generally) Positive and negative

Economic Impact

Top of page

Invasion of A. hockii in natural and semi-managed grasslands can drastically reduce stocking density by impeding access to livestock and by reducing the presence and growth of palatable forage species due to competition for light and water.

A. hockii also harbours the unpalatable grass Cymbopogon afronardus [Cymbopogon nardus] by restricting grazing and trampling beneath it. The costs of removing A. hockii and recouped costs from increased cattle production are discussed by Harrington (1970).

Social Impact

Top of page

In Ankole, Uganda, Harley and Pilson (1961) considered that the presence of tall A. hockii shrubs prevented effective control of tsetse fly (Glossina morsi-tans Westw.).

Risk and Impact Factors

Top of page

Uses

Top of page

The species has a wide range of uses throughout its native range as a source of fuelwood, exudate gum, resins, bee forage, bark fibre and fodder, as well as having various medicinal uses (Burkill, 1985).

The wood has moisture content of 12% and air-dry wood density of 0.58-0.64 g/cm3 (Bolza and Keating, 1972). The timber is hard and straight grained, but its small bole size, susceptibility to termites and decay and availability of other species means that it is not reported as a source of sawn timber. Small wood is used in rustic construction for homes and shade housing for cattle, and thorny branches are used for cattle pens and fencing. Where common, it is often used as a source of firewood, and the high fixed carbon in A. hockii makes it ideal for charcoal making (pyrolysis) (Musinguzi et al, 2012).

A. hockii produces tannins in comparable amounts to the black wattle A. mearnsii, but the protein precipitating capacity of A. hockii is different, suggesting that poor quality leather would be produced. However, mixtures of extracts from different native Acacia species resulted in protein precipitating profiles similar to that of wattle extract (Mugedo and Waterman, 1992). The bark also yields a fibre for rope making and basketry in Tanzania.

Leaves form part of the diet of native species and livestock, as do pods and seeds (Gwyne, 1969). Foliage and pods are browsed by goats, flowers are eaten by baboons, seed by chimpanzees, and elephants and antelope seek out the dry pods and new leaves after fires (Wickens et al., 1995). Chemical and mineral composition suggest that A. hockii has low nutritive value compared to 15 indigenous Kenyan browse plants selected by Ondiek et al. (2010), and medium palatability amongst 40 species tested in Ethiopia (Kaitho et al., 1996), with high levels of tannins in the leaves (Kaitho et al., 1998).

The flowers are sweet scented and are a good source of bee forage (Wickens et al., 1995). A. hockii leaves are also reported as a feed for the African wild silkmoth Gonometa postica (Lepidoptera: Lasiocampidae) (Ngoka et al., 2007), though it is not known whether there is any commercial production.

The inside of the bark is edible as a famine food. Inner bark fibre is also chewed for its juice, which has a sweet taste, and the Maasai chew the white inner bark to slake thirst.

The species also yields an edible, translucent, reddish exudate gum. Its chemical composition was reported in Anderson et al. (1984). Wickens et al. (1995) stated that it is marketed as African gum arabic but is inferior to true gum arabic from A. senegal. It is used by the Mbeere tribe in Kenya as an adhesive.

Many medicinal uses are reported, including as a pain killer, vermifuge and to treat stomach troubles, dropsy, swellings, oedema and gout (Burkill, 1985). In Kenya it has been used against malaria, abdominal pains and applied to abscesses, and in Tanzania, boiled bark is given to children with fever, and a root decoction is taken for hookworm, and for the treatment of tuberculosis and related ailments in Uganda (Tabuti et al., 2010).

Uses List

Top of page

Animal feed, fodder, forage

  • Fodder/animal feed
  • Forage

Environmental

  • Agroforestry
  • Land reclamation
  • Revegetation
  • Soil conservation
  • Soil improvement

Fuels

  • Charcoal
  • Fuelwood

Human food and beverage

  • Emergency (famine) food
  • Honey/honey flora

Materials

  • Bark products
  • Fibre
  • Gums
  • Tanstuffs

Medicinal, pharmaceutical

  • Traditional/folklore

Similarities to Other Species/Conditions

Top of page

A. hockii may be confused with the closely related A. seyal, as both share similarly coloured peeling bark, tree form, size and general morphology. Means for their separation in the field include the presence of powdery bark in A. seyal which is not present in A. hockii, and the pods of A. seyal, which are glabrous as opposed to those of A. hockii which are usually puberulous. A. hockii twigs are usually more elongate, slender and puberulous than those of A. seyal, and have reddish or brownish bark which does not peel to expose the inner layer, a characteristic of A. seyal. A. hockii also prefers moister savannah zones as compared to A. seyal, which tolerates drier sites (Burkill, 1985).

Prevention and Control

Top of page

Cultural Control and Sanitary Measures

Harrington (1974) experimented with the use of fire for controlling dense stands of A. hockii approximately 3.5 m high in Uganda, on a savannah pasture dominated by Cymbopogon afronardus, Hyparrhenia filipendula and Themeda triandra. Treatments were fire protection, early and late triennial burns, early and late annual burns and two burns per year, applied to four grazing managements. Clear differences were apparent in both the grass sward and the structure of the shrub layer after three years. With no fire, the A. hockii stand became a tangle of interlocked branches which restricted cattle movement. Early annual burning and two burns per year both produced relatively open grassland with stunted bushes. Late annual burning caused a denser bush growth than early burning, but as the bushes were mainly single stemmed with few low branches, cattle movement was not greatly impeded.

In Cameroon, Peltier and Eyog-Matig (1989) found that the rate of production of A. hockii, Dichrostachys glomerata and Piliostigma was 0.15 and 0.18 m3/ha for unbrowsed but burned stands (fires early or late in the dry season, respectively), and 0.20 m3/ha for browsed plots and 0.41 m3/ha on burned plots. Browsing improved wood production by reducing competition from herbaceous vegetation and the restriction of fire is seen as crucial to successful regeneration of these woody species.

Physical/Mechanical Control

Manual weeding with a hoe is a widely used control method in Uganda, but it takes up to 50-75% of farmers' time, and with labour being scarce and very expensive, weeding is often delayed by a month or more, and use of oxen and tractor-mounted equipment is impracticable in many situations (Wetala, 1978). Small trees can regrow their biomass in 3-4 years, and if wood harvesting is reduced to below four years, this can help to prevent rapid invasion of A. hockii and help the recolonisation of natural pastures.

Chemical Control

The earliest record of chemical control is Harker (1959), who reported that a 2:1 mixture of 2, 4-D and 2,4,5-T in dieseline gave only 25% control after 6 months when applied to cut stems, though mortality increased to 88% when trees were burnt after spraying. Application to tree trunks 6-10 cm in diameter was ineffectual, but gave good control on regrowth from cut stumps. However, 2,4,5-T is now banned and should no longer be used.

In western Uganda, foliar applications of picloram gave more effective control of A. hockii than picloram granules or foliar treatment with 2, 4-D + picloram (Anon., 1968; Harrington, 1968). Harrington (1968) also found that A. hockii was more susceptible to applications applied in February, August, September and October than in other months, when applications killed 30-80% of trees, though with no apparent advantage in spraying at any particular time of day

Harrington (1970) found that applications of picloram to cut stumps of 20 cm diameter was more efficient than foliar applications, and observed that vigourous regrowth 12 months after treatment had died back after 19 months. A stump treatment of a 4:1 mixture of 2, 4-D and picloram (much cheaper than pure picloram at the time) killed 100% of plants (Harrington, 1970).

In trials established in 1968 in Uganda, picloram or a 4:1 mixture of 2,4-D + picloram were applied to A. hockii bushes by (a) a technique that simulated aerial spraying, and (b) spraying directly on the foliage (Harrington, 1972). Results in November 1969 showed that (a) was unsatisfactory but (b) killed more than 70% of plants, although only at the higher herbicide concentrations. However, the last result was poorer than results in previous trials, possibly due to moisture stress inhibiting herbicide translocation. Supplementary application of picloram granules improved the mortality rate but not enough to warrant the expense. The 2,4-D + picloram mixture gave a poorer mortality rate than picloram alone even when the solutions contained the same amount of picloram. Previous burning of treated areas affected the results, but also made the movement of spraying teams much easier (Harrington, 1972).

In experiments carried out at Ankole, Uganda (Harrington, 1973a), A. hockii bushes less than 3 m high with trunks 3-10 cm in diameter were cut at about 15 cm above ground and the stumps treated on five different dates with the following herbicides: picloram diluted 2:1 with water, picloram + 2,4-D both undiluted and diluted 2:1 with water and a commercial 2,4-D + 2,4,5-T (now banned) mixture diluted 40:1 in dieseline. Picloram treatments gave the best results and were more effective and cheaper than the 2,4,5-T + 2,4-D mixture. June treatments were least effective but August treatments killed 100% of plants. Prior burning of bushes increased their susceptibility to herbicides. Burning after treatment had no effect. In Ankole and Masaka districts, A. hockii is usually associated with the grass weed Cymbopogon afronardus and it is desirable to clear both species at the same time (Harrington, 1973a).

In contrast, however, Harrington (1973b) also draws attention to the possibility that expensive clearance of bush (and especially of A. hockii) on savannah grazing land in Uganda may not lead to any appreciable increase in grazing value, and discusses the possible reasons for this, including loss of fertility from leaf-fall, insects and birds, loss of shade, and an increased rate of surface soil drying.

Monitoring and Surveillance (incl. Remote Sensing)

Mapping is an important tool in aiding management decisions. Spatial prediction showed the potential distribution of A. hockii in Burkina Faso, highlighting the areas of high and low occurrence, useful for the management and valorization of forest resources under climate change and growing human pressure. Validation showed that the models for A. hockii were stable and adequate, with a high Spearman correlation value of 0.84 (Traoré et al., 2008).

References

Top of page

Anderson DMW; Bridgeman MME; Pinto Gde, 1984. Acacia gum exudates from species of the series Gummiferae. Phytochemistry, 23(3):575-577.

Anonymous, 1968. Use of arboricides in the control of Acacia hockii. Report. Entebbe, Uganda: Animal Health Research Centre, 40-42.

Bolza E; Keating WG, 1972. African timbers - the properties, uses and characteristics of 700 species. Melbourne, Australia: CSIRO Division of Building Research.

Burkill HM, 1995. The useful plants of West Tropical Africa. Vol. 3: Families J-L. Richmond, UK: Royal Botanic Gardens Kew.

GBIF, 2012. Global Biodiversity Information Facility. Global Biodiversity Information Facility (GBIF). http://data.gbif.org

Gwyne MD, 1969. The nutritive values of Acacia pods in relation to Acacia seed distribution by ungulates. East African Wildlife Journal, 7:176-8.

Hall JB; McAllan A, 1993. Acacia seyal: a monograph. School of Agricultural and Forest Sciences Publication, University of Wales, No. 4, 1; 11 pp. of ref.

Hamant C; Lescanne N; Vassal J, 1975. Some new chromosome numbers in the genus Acacia. Travaux, Laboratoire Forestier de Toulouse, Tome I, Vol. IX, Art. VIII. 4 pp.

Harker KW, 1959. An Acacia weed of Uganda grassland. Tropical Agriculture, Trinidad and Tobago, 36(1):45-51.

Harley JMB; Pilson RD, 1961. An experiment in the use of discriminative clearing for the control of Glossina morsi-tans Westw. in Ankole, Uganda. Bulletin of Entomological Research, 52:561-576.

HARRINGTON GN, 1968. The effect of picloram on Acacia hockii de Wild. when applied in different months, different times of day and in different formulations. In: Proceedings 9th Brit. Weed Control Conf. 827-831.

Harrington GN, 1970. The effect of picloram on Acacia hockii de Wild. A summary of experiments carried out in Ankole, Uganda. In: 4th E. Afr. Herbicide Conference, Arusha. 11.

Harrington GN, 1972. The effect of foliar spraying of Acacia hockii de Wild. with picloram and 2,4-D/picloram mixtures and additional treatment with picloram granules. East African Agricultural and Forestry Journal, 37(3):197-200.

Harrington GN, 1973. Bush control [in Uganda]. A note of caution. East African Agricultural and Forestry Journal, 39(1):95-96.

Harrington GN, 1973. The eradication of Acacia hockii from Ugandan rangeland using stump treatment with picloram and notes on effects on productivity. PANS. Pest Articles and News:76-86.

Harrington GN, 1974. Fire effects on a Ugandan savanna grassland. Tropical Grasslands, 8(2):87-101.

Hutchinson J; Dalziel JM, 1958. Flora of West Tropical Africa. Vol. 1 Part 2, 2nd ed. (rev.). Revised by Keay RWJ.

ILDIS, 2013. International Legume Database & Information Service. Reading, UK: School of Plant Sciences, Unversity of Reading. http://www.ildis.org/

Kaitho RJ; Nsahlai IV; Williams BA; Umunna NN; Tamminga S; Bruchem Jvan, 1997. Relationships between preference, rumen degradability, gas production and chemical composition of browses. Agroforestry Systems, 39(2):129-144; 30 ref.

Kaitho RJ; Umunna NN; Nsahlai IV; Tamminga S; Bruchem Jvan; Hanson J; Wouw Mvan de, 1996. Palatability of multipurpose tree species: effect of species and length of study on intake and relative palatability by sheep. Agroforestry Systems (Netherlands), 33(3):249-261.

Kiyingi I; Kidiya JM; Gwali S; Okullo P; Byabashaija DM, 2010. Tree species composition, structure and utilisation in Maruzi Hills Forest Reserve in Uganda. Southern Forests: a Journal of Forest Science, 72(2):113-117. http://www.informaworld.com/smpp/content~db=all~content=a926650706~frm=titlelink

Maundu PM; Ngugi GW; Kabuye CHS, 1999. Traditional Food Plants of Kenya. Nairobi, Kenya: National Museum of Kenya, 288 pp.

Missouri Botanical Garden, 2013. VAScular Tropicos database. Missouri, USA: Missouri Botanical Garden. http://mobot.mobot.org/W3T/Search/vast.html

Mitiku Tikssa; Tamrat Bekele; Ensermu Kelbessa, 2010. Plant community distribution and variation along the Awash River corridor in the main Ethiopian rift. African Journal of Ecology, 48(1):21-28. http://www.blackwell-synergy.com/loi/aje

Mugedo JZA; Waterman PG, 1992. Sources of tannin: alternatives to wattle (Acacia mearnsii) among indigenous Kenyan species. Economic Botany, 46(1):55-63.

Musinguzi WB; Okure MAE; Wang L; Sebbit A; Løvas T, 2012. Thermal characterization of Uganda's Acacia hockii, Combretum molle, Eucalyptus grandis and Terminalia glaucescens for gasification. Biomass and Bioenergy, 46:402-408. http://www.sciencedirect.com/science/journal/09619534

NARO, 2004. Implementation of invasive plant prevention and control programmes in Uganda. Report submitted to the CAB International Africa Regional Centre under the PDF-B phase of the UNEP/GEF Project: Removing Barriers to Invasive Plant Management in Africa. Entebbe, Uganda: National Agricultural Research Organisation.

Neba NE, 2009. Management of woody plants in indigenous land use systems of the Sahel: example of north Cameroon. International NGO Journal, 4(11):480-490. http://www.academicjournals.org/INGOJ/PDF/Pdf2009/Nov/Neba.pdf

Ngoka BM; Kioko EN; Raina SK; Mueke JM; Kimbu DM, 2007. Semi-captive rearing of the African wild silkmoth Gonometa postica (Lepidoptera: Lasiocampidae) on an indigenous and a non-indigenous host plant in Kenya. International Journal of Tropical Insect Science, 27(3/4):183-190. http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1662288&fulltextType=RA&fileId=S1742758407883160

Nyende KO, 1998. MSc Thesis. Nairobi, Kenya: Univeristy of Nairobi.

Ondiek JO; Abdulrazak SA; Njoka EN, 2010. Chemical and mineral composition, in-vitro gas production, in-sacco degradation of selected indigenous Kenyan browses. Livestock Research for Rural Development, 22(2):25. http://www.lrrd.org/lrrd22/2/ondi22025.htm

Parker C; Caton BP; Fowler L, 2007. Ranking nonindigenous weed species by their potential to invade the United States. Weed Science, 55(4):386-397. http://wssa.allenpress.com/wssaonline/?request=index-html

Peltier R; Eyog-Matig O, 1989. Silvo-pastoral trials in N. Cameroon. Experiments to study regeneration and management in a degraded tree savanna in the Sudo-Sahelian zone at Laf-Badjava. First results. (Un essai sylvo-pastoral au Nord-Cameroun. Mise en place d'un dispositif d'étude de la régénération et de la gestion d'une savane arborée dégradée en zone soudano-sahélienne à Laf-Badjava, premiers résultats.) Bois et Forêts des Tropiques, No. 221:3-23.

Renard R; Lambinon J; Reekmans M; Veken PVan der; Govaert M, 1983. Chromosome numbers of some angiosperms of Rwanda, Burundi and Kenya. (Nombres chromosomiques de quelques angiosperms du Rwanda, du Burundi et du Kenya.) Bulletin du Jardin Botanique National de Belgique, 53(3/4):343-371.

Seigler DS; Ebinger JE, 2010. New combinations in Senegalia and Vachellia (Fabaceae: Mimosoideae). Phytologia, 92(1):92-95.

Soromessa T; Teketay D; Sebsebe Demissew, 2004. Ecological study of the vegetation in Gamo Gofa zone, southern Ethiopia. Tropical Ecology, 45(2):209-221.

Tabuti JRS; Kukunda CB; Waako PJ, 2010. Medicinal plants used by traditional medicine practitioners in the treatment of tuberculosis and related ailments in Uganda. Journal of Ethnopharmacology, 127(1):130-136. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T8D-4XBR4N5-1&_user=10&_coverDate=01%2F08%2F2010&_rdoc=21&_fmt=high&_orig=browse&_srch=doc-info(%23toc%235084%232010%23998729998%231578027%23FLA%23display%23Volume)&_cdi=5084&_sort=d&_docanchor=&_ct=30&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=bdebc9c21d3c1cb3240f7f822fcad986

Traoré S; Kaboré O; Thiombiano L; Rasolodimby-Millogo J, 2008. Spatial prediction and distribution modelling of Acacia spp. in Eastern Burkina Faso. (Prédiction spatiale et modélisation de la distribution des Acacia spp. dans l'Est du Burkina Faso.) Sécheresse, 19(4):283-292.

USDA-ARS, 2013. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx

Vassal J, 1972. Ontogenetic and seed research applied to the morphological, taxonomic and phylogenetic study of the genus Acacia. Travaux de Laboratoire Forestier de Toulouse, Tome 1, Vol. 8, art. 17. 125 pp.

Wetala MPE, 1980. Weed problems and control practices in Uganda. In: Weeds and their control in the humid and subhumid tropics. Proceedings of a Conference at the International Institute of Tropical Agriculture, 1978. 213-220.

Wickens GE; Seif El Din AG; Sita G; Nahal I, 1995. Role of Acacia species in the rural economy of dry Africa and the Near East. F.A.O. Conservation Guide, No. 27:138 pp.

Contributors

Top of page

04/11/13 Original text by:

Nick Pasiecznik, consultant, France

Distribution Maps

Top of page
You can pan and zoom the map
Save map
Download KML file Download CSV file
Creative Commons Licence
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

Please click OK to ACCEPT or Cancel to REJECT

Creative Commons Licence
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

Please click OK to ACCEPT or Cancel to REJECT