Camelthorn as firewood
Camelthorn is great firewood in Southern Africa. It got an outer layer of light-colored sapwood and dark, hard, and heavy heartwood inside. This hardwood produces long-lasting coals and high heat. Camelthorn occurs from the Northern Cape province of South Africa to Angola and Zambia as its northernmost area of distribution.
How did the name for Camelthorns arise?
Camelthorn (Vachellia erioloba) got its English common name from the Afrikaans name for giraffes. When the Dutch Boers landed 1652 in South Africa, they found a variety of exotic plants and animals, for which they did not have a name for. When they saw giraffes, they thought these were camels with a gait of horses. And therefore called them ‘Kameelperd’ (Camelhorse). When Carl Linnaeus named giraffes in 1758, he took for the species name the Afrikaans word and called them Giraffa camelopardalis. And as giraffes liked to feed on the pods of this thorn tree, the common name of ‘Camelthorn’ stuck.
Why is Camelthorn not an acacia?
The development of the scientific name for this tree is interesting and stormy. From 1754 up to 2011 it was called Acacia erioloba. ‘Acacia’ is self-explaining, and ‘erioloba’ means ‘wooly lobe’, as the pods look very much like velvety haired earlobes of humans. But then, an emotional battle between scientist from Australia vs. South Africa evolved about the scientific naming of the group of yellow-flowered, pod producing plants known as wattles, mimosas, thorn trees, and acacias. And at the end, Australians won. At the 17th International Botanical Congress, held in Melbourne in 2011, it was decided that all African species of this group will be newly grouped into the genera Vachellia and Senegalia (Mimosas). See here. Therefore, no acacias are native to Africa any more. And due to having spines and round, head-like flowers, Camelthorn was grouped into the genus Vachellia.
Value of Camelthorn as firewood
Average dried weight (density) of the heartwood is around 74 lbs/ft3 (1,185 kg/m3) according to Wood database.
Densities of other woods for comparison are as follows:
- African Blackwood (Dalbergia melanoxylon): 79 lbs/ft3 (1,270 kg/m3) – that’s the hardest wood in Africa
- European beech (Fagus sylvatica): 44.3 lbs/ft3 (710 kg/m3)
- English Oak (Quercus robur): 42 lbs/ft3 (675 kg/m3)
- Scots pine (Pinus sylvestris): 34 lbs/ft3 (550 kg/m3)
Not only the density of Camelthorn wood is high, but also its calorific value, when burning.
As Dr. Martina Meincken writes in this article: ‘The calorific value of wood can be related to its chemical composition and varies between 17 – 20 MJ/kg for oven-dry wood. Major elements contributing to the calorific value are carbon, hydrogen, and oxygen, whereas nitrogen and some inorganic components contribute to toxic waste gases.’
According to this source, Camelthorn wood has got a calorific value of 19,03 MJ/kg as high wood densities are directly related to high calorific values. This results into a high energy content (high heat) and slow burning process.
Disadvantage of Camelthorn as firewood
There is one – small – setback of Camelthorn wood. This is the ash content, which is around 2,8% of burned volume. Ideally, the remaining ash amount should be below 1% in order to optimize energy output and to be able to roast meat directly on the coals. Therefore, gridles should be used for roasting, when burning camelthorn firewood.
Other uses of Camelthorn trees
All other uses of Camelthorn trees will be described in future articles. At this point it should suffice to give a very brief overview of these uses. From wounds in the cambium layer of camelthorn trees, an edible and sweet tasting gum is oozing. The color of this gum is amber and transparent and local people, monkeys, baboons, but also birds like to eat it. The stripped and pounded inner bark is used for ropes and strings. The spongy inside layer of young pods was used as famine food by Topnaar people in the Kuiseb area. And ripe seeds can be roasted and ground to produce a substitute for coffee.
Lessons learned about Camelthorn as firewood:
- Both, English common- and its scientific names got an interesting history.
- Camelthorn wood got a very high average dried weight (density) and high calorific value when burning.
- In combination with its high carbon content, it produces lots of heat and burns slowly.
- Disadvantage is an elevated ash content, which is not ideal for roasting food directly on the coals.
- Besides of prime firewood, camelthorn trees also deliver edible gum and inner bark strings.