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. The base of older thorns frequently houses ant galls up to 2 cm across 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, with many other species and ecosystem parameters dependent on it. At the same time, this tree provides valuable resources 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, and as highly nutritional fodder for cattle (although leaves and pods produce prussic acid in quantities that poison livestock at some times of the year); edible and medicinal gum and bark. Although it is a hardy species, frost and drought resistant, A. erioloba is slow-growing, slow to propagate and of most value as a large established tree. The large trees, however, are vulnerable; they are regularly cleared for agricultural and grazing development as well as harvested for lumber and for what is considered high quality charcoal and firewood. This species has protected status in South Africa.
(Arid Zone Trees 2003-2013; Orwa et al. 2009; Seymore and Milton 2003)
The species distribution includes Zimbabwe, southern Zambia, eastern Botswana, northern Namibia, southern Angola and throughout much of South Africa from the Cape to Gauteng, Mpumalanga and Limpopo Provinces.
Camel thorn is a rounded tree or large shrub in growth form, attaining a height of up to 15 metres. The main stem exhibits furrowed dark grey bark, with younger branches being reddish-brown in colour. The thorns are straight, occurring in pairs that are typically basally fused. Leaves are 2-compound, with two to five pairs of pinnae; moreover, there are eight to fifteen pairs of greyish green leaflets. Side veins are prominent both above and below. The species lacks a petiolar gland, although a minute gland is manifested at the junction of each pair of pinnae. Flowers appear in the form of yellow spheres, and fruit is a hard, hairy ear-shaped woody pod.
Molecular Biology and Genetics
Statistics of barcoding coverage: Acacia erioloba
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1
Vachellia erioloba (camel thorn, giraffe thorn, Afrikaans: Kameeldoring, Tswana: Mogôtlhô, Sotho: Mogohlo) is a southern African legume. Its preferred habitat is the deep dry sandy soils of the Transvaal, western Free State, northern Cape Province, Botswana, and the western areas of Zimbabwe and Namibia. The tree was first described by Ernst Heinrich Friedrich Meyer and Johann Franz Drège in 1836.
The tree can grow up to 17 metres high and is commonly found in Namibia. Its name refers to the fact that giraffe (kameelperd in Afrikaans) and camels commonly graze on the harder-to-reach succulent leaves normally out of reach of smaller animals. Giraffe in particular are partial to all vachellias and manifest a specially-adapted tongue and lips that can cope with the vicious thorns. It also grows ear-shaped pods, which are favoured by a large number of herbivores including cattle. The wood is dark reddish-brown in colour and extremely dense and strong. It is slow-growing, very hardy to drought and fairly frost-resistant.
The wood is a good fuel for fires, which leads to widespread clearing of dead trees and the felling of healthy trees. According to superstition, lightning will strike at V. erioloba more often than other trees. The camel thorn's seeds can be roasted and used as a substitute for coffee beans. The camel thorn is a protected tree in South Africa.
Mokala Bark on a tree near Potgietersrust in Transvaal, South Africa
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- Kyalangalilwa B, Boatwright JS, Daru BH, Maurin O, van der Bank M. (2013). "Phylogenetic position and revised classification of Acacia s.l. (Fabaceae: Mimosoideae) in Africa, including new combinations in Vachellia and Senegalia.". Bot J Linn Soc 172 (4): 500–523. doi:10.1111/boj.12047.
- "Protected Trees". Department of Water Affairs and Forestry, Republic of South Africa. 3 May 2013.
- The type specimen of Acacia giraffae, proved on closer examination to be a hybrid of V. haematoxylon and the species which would later become known as V. erioloba. The name V. erioloba was therefore proposed for the vast numbers of camel thorn which are not hybrids.
- USDA Germplasm Resources Information Network entry for Vachellia erioloba (as Acacia erioloba)
- Mhloniswa Dlamini; Walter Sisulu (2005). "Acacia erioloba". PlantzAfrica. South African National Biodiversity Institute. Retrieved 11 November 2014.
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