Acacia erioloba, known as Giraffe Thorn or as Camel Thorn (a mistranslation from the Afrikaans name “Kameeldoring”, meaning Giraffe Thorn) is an African species in the large and taxonomically controversial Acacia genus. It is the dominant tree, highly recognizable, on the Kalahari plains in Angola, Botswana, Mozambique, Namibia, South Africa, Zambia, and Zimbabwe, often growing in and along the banks of riverbeds.
Camel Thorn trees grow up to 18 m tall, with a large spreading canopy that produces shade and animal shelter. Trees older than 10 years produce numerous yellow ball-shaped inflorescences, and trees older than 20 years produce crops of up to 1,200 flat, crescent-shaped seedpods per tree. Studies suggest that trees may live 250-300 years. Large herbivores, including black rhinos, elephants, giraffes, gemsbok, elands and kudus are agents of seed dispersal as they eat large numbers of pods, passing the seeds with their tough seed coats through their gut intact and then providing excellent germination conditions in the dung they expel with the seed. The trunk of A. erioloba, like many Acacia species, is covered with paired thorns about 2-5 cm long (a feature common to many Acacia species); older thorns frequently have ant galls up to 2 cm at the base used as protection by a large invertebrate fauna. The tap root can grow up to 60 m, allowing this tree to access deep ground water sources.
Acacia erioloba is considered a keystone species in its habitat, with many other species and ecosystem parameters dependent on it. This tree also provides many values to people: dark, hard, insect-resistant wood for lumber also considered excellent for fuel and cooking purposes; abundant, nutritious pods sometimes used to make a hot coffee-like drink or porridge are also used as highly nutritional fodder for cattle along with the leaves (although both leaves and pods are reported to poison livestock at some times of the year through production of prussic acid); edible and medicinal gum and bark. Although it is a hardy species, frost and drought resistant, it is slow-growing, slow to propagate and mostly valuable as large established tree. Furthermore, A. erioloba is regularly cleared for agricultural and grazing development as well as harvested for lumber and for what is considered high quality charcole and firewood. This species has protected status in South Africa.
(Arid Zone Trees 2003-2013; Orwa et al. 2009; Seymore and Milton 2003)
- Arid Zone Trees 2003-2013. Acacia erioloba, Camel Thorn or Giraffe Thorn. Retrieved 5/17/13 from http://www.aridzonetrees.com/AZT%20Interactive%20Buttons/Tree%20Index/Cut%20sheets/Acacia/Acacia%20erioloba.htm
- Barnes RD et. al. 1997. Acacia erioloba monograph and annonated bibliography. Tropical Forestry Papers No. Oxford Forestry Institute. Oxford University Press.
- Coates-Palgrave K. 1988. Trees of southern Africa. C.S. Struik Publishers Cape Town.
- Erkkila A, Harri S. 1992. Silva Carelica Forestry in Namibia 1850-1990. University of Joensuu.
- Orwa, C, Mutua, A, Kindt, R, Jamnadass, R, Simons, A. 2009. Agroforestree Database: a tree reference and selection guide version 4.0. Retrieved May 17, 2013 from http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=40 (also available in pdf form: http://www.worldagroforestry.org/treedb2/AFTPDFS/Acacia_erioloba.pdf)
- Palmer E, Pitman N. 1972. Trees of Southern Africa Vol. 2. A.A. BalKema Cape Town.
- Seymore, C. and Milton, S. 2003. A collation and overview of research on Acacia erioloba (Camel Thorn) and identification of relevant research gaps to inform protection of the species. Department of water affairs and forestry. Contract No. 2003/089. Retrieved May 17, 2013 from http://dev.landbou.com/content/uploads/ArticleDocument/Kameeldoring_Acacia_Erioloba_Report_2003.pdf
- Storrs AEG. 1995. Know your trees: some common trees found in Zambia. Regional Soil Conservation Unit (RSCU).
- Tietema T, Merkesdal E and Schroten J. 1992. Seed germination of indigenous trees in Botswana. Acts Press.
- Timberlake J, Fagg C and Barnes R. 1999. Field guide to the Acacias of Zimbabwe. CBC Publishings, Zimbabwe.
- Timberlake J. 1980. Handbook of Botswana Acacias. Ministry of Agriculture, Botswana.
- Venter F, Venter J-A. 1996. Making the most of Indigenous trees. Briza Publications.