AgroForestryTree Database
Acacia holosericea
 Species identityEcology and distributionPropagation and managementFunctional usesPests and diseasesAdditional InfoBibliographyImages |
Species identity
TaxonomySynonym(s)
Common names
(English) : candelabra wattle
Botanic description
Acacia holosericea attains an average height of less than 8 m, with numerous branches beginning from the base, giving it a multi-stemmed appearance. The bark is smooth and green in the young plant. Phyllodes measure 10-25 x 1.5-10 cm, are thick, with 3-5 longitudinal veins. Flowers small, bright yellow, cattail-like spikes, 3-6 cm long. Pods narrow, coiled, 3-6 x by 2.5-5 cm, in dense clusters; contain small, oval, slightly flattened, shiny, black seeds measuring 2 x 3-5 mm. The generic name acacia comes from the Greek word ‘akis’, meaning a point or a barb. The species name is derived from the Greek 'holo' (entire/whole) and the Latin 'sericeus' (silky, with long straight close-pressed glossy hairs), in reference to the indumentum of the plant.
Ecology and distribution
Natural HabitatThe early and abundant seeding of A. holosericea has the potential of making it a weed.
Geographic distribution
Native : Australia
Exotic : Burkina Faso, India, Kenya, Niger, Nigeria, Senegal, Sudan
Biophysical limitsAltitude: 150-450 m, Mean annual temperature: 19.5-34.7 deg. C, Mean annual rainfall: 600-1 200 mm Soil type: Grows on a wide range of soils from shallow acidic sandy lithosols, shallow loams, red volcanic and solodized solonets soils.
Reproductive Biology
Like most acacias, A. holosericea relies on sexual reproduction. It produces a large number of flowers, a small proportion of which develops into fruit. It is pollinated by the activity of insects and birds. Seed dispersal is prompted by propulsion from drying dehiscent pods. Browsing vertebrates sometimes also play a role in seed dispersal. In its native range in Australia, The main flowering period is June-August but can be April-October. Fruits mature in August-October.
Propagation and management
Propagation methodsNatural vegetation from self-seeding occurs freely in the native habitat of A. holosericea. Planting seedlings in polythene bags is the most reliable method of artificial propagation. For successful germination, boiling water should be poured over the seeds, after which they are soaked for 24 hours.Tree Management
Lopping and pollarding are recommended. Generally A. holosericea does not coppice well.
Germplasm Management
Seed storage behaviour is orthodox; 11% viability lost after 14 years storage at room temperature. There are 100 000-175 000 seeds/kg. Seed pretreatment with boiling water for 1 minute is necessary to break dormancy and enhance germination.
Functional uses
ProductsFood: Seeds are edible, but consumption is limited by chances of toxicity, the labour-intensive procedure of preparating them for making flour, and their unpleasant odour. Fodder: Large quantities of phyllode biomass, produced during the dry season when other acacias shed their leaves, is a valuable fodder source. However, fodder should be dried before it is fed to livestock, as fresh phyllodes are not palatable for cattle and sheep, and there are reports from Niger of goats dying after consuming them. Crude proteins and digestibility are low, due to their high concentrations of tannins, which limit the availability of the protein component. Trees 4 years old have reportedly produced about 3 t/ha of dry phyllodes. Fuel: The wood, an excellent fuel that can readily be converted to charcoal, is hard with high density (ca. 870 kg/cubic meter). The calorific value of wood is estimated at 4670 kcal/kg and of charcoal 7536 kcal/kg. Early rapid growth makes A. holosericea a highly productive fuelwood source. Trees 4 years old can yield up to 13 t/ha.Services
Shade or shelter: Due to its large dense crown, A. holosericea is used to form the lower part of a multistorey windbreak with Eucalyptus camaldulensis. Reclamation: Grows fast, has a dense crown, fixes nitrogen and has vigorous colonizing characteristics. These make it ideal for revegetation and restoration of degraded mining sites and fixation of sand dunes. Ornamental: A. holosericea is becoming a popular species for planting in towns and for roadside windbreaks. The silvery foliage, early appearance of its yellow flower spikes and prominent twisted pods make it an attractive ornamental shrub. Its relatively short life span of 4-8 years is a limiting factor.
Pests and diseasesests recorded Insect pests recorded include Myllocerus spp and Sextius spp. Fungi causing diseases include Aecidium, Fusarium oxysporum, Meloidogyne and Uromyces digitatus.
Bibliography
Doran CJ, Turnbull JW (eds.). 1997. Australian trees and shrubs: species for land rehabilitation and farm planting in the tropics. ACIAR monograph No. 24, 384 p.Hocking D. 1993. Trees for Drylands. Oxford & IBH Publishing Co. New Delhi.
Hong TD, Linington S, Ellis RH. 1996. Seed storage behaviour: a compendium. Handbooks for Genebanks: No. 4. IPGRI.
ICRAF. 1992. A selection of useful trees and shrubs for Kenya: Notes on their identification, propagation and management for use by farming and pastoral communities. ICRAF.
New TR. 1984. A biology of acacias. A new source book and bibliography for biologists and naturalist. Oxford University Press. Melbourne.
Thomson LAJ. 1989. Report to ACIAR on visit to Kenya and West Africa (Burkina Faso, Niger, Nigeria and Senegal) 27 March-6 May 1989. 50pp (unpublished).
Turnbull JW. 1986. Multipurpose Australian trees and shrubs: lesser-known species for fuelwood and agroforestry. ACIAR Monograph No. 1.
Turnbull JW. 1988. Acacia holosericea - a successful newcomer for the dry tropics. Nitrogen Fixing Tree Association Highlights. Nitrogen fixing tree Association.
Vogt K. 1995. A field guide to the identification, propagation and uses of common trees and shrubs of dryland Sudan. SOS Sahel International (UK).