Plant of the Month 1
Arabic name: Samr, Samar
Common name: Umbrella Thorn
Family name: Fabaceae
Found: Arabia, Africa
Photo Credits: Alexey Sergeev, Flora of Qatar (All images from Qatar)
Acacia tortilis is known to tolerate high alkalinity, drought, high temperatures, sandy & stony soils, strongly sloped rooting surfaces, and sand blasting. It occurs from sand dunes to rocky scarps. A tough resistant species, the umbrella thorn grows in areas of annual rainfall as low as 40 mm & dry seasons of 1-12 months.
Acacia tortilis is very prevalent and familiar in the Qatar landscape. Its presence provides the reassuring quality of unconscious recognition of place. Currently, the tree is under pressure due to rapid development, but replanting initiatives led by QF’s Qur’anic Botanic Garden team are the start of reversing this trend.
This slow growing tree flowers in April- July with dense, packed white florets, but flowering can be sporadic depending on rain. It has the classic, umbrella-shaped canopy associated with thorn trees, reaching heights of between 5-20 m in nature. Bird species take advantage of the height and build nests in the canopy.
The bark has a rough feel and is grey to black in colour. The tree has a combina on of one straight thorn with a small hooked thorn alongside. The thorns are thin and grow in pairs. The flowers form in clusters on old wood. Flowers are creamy, white, balls and pods are pale, gold brown in colour, curled and twisted. Leaves are very small giving a soft, feathery appearance. Browsing animals eat the leaves together with the thorns, the latter more easily when young and soft. The older, hardened thorns can be a deterrent to over-browsing.
Timber from the tree is used for furniture, wagon wheels, fence posts, cages, and pens. The pods and foliage, which grow prolifically on the tree, are used as fodder for desert grazing animals. The bark has been used as a string medium and is a source for tannin. Gum from the tree is edible and can be used as Gum Arabic. Parts of the tree including roots, shoots, and pods are also often used by for a vast number of purposes including decoration, weapons, tools, and medicines.
The Umbrella thorn is also an important species for rehabilitation of degraded arid land; it tolerates drought, wind, salinity and a wide range of soil types, and has the additional benefit of fixing nitrogen - an essential plant nutrient - in the soil via its interaction with symbiotic root bacteria. It is the tree most recommended for reclaiming dunes in India and Africa. The bark is said to be a good source of tannin and local artists have used the pods to form necklaces. In African nations the roots made spear shafts and fish spears. Desert dwelling nomads often use the flexible roots for frameworks of their temporary shelters. The pods and leaves are high in nutrition and browsed by game and livestock who eat the young green pods; other animals eat the pods which fall to the ground. It is extensively browsed by camels.
Digital 3D - Commercial Car Park Edge (3D images by )
Digital 3D - Residential Street (3D images by )
Digital 3D - Urban Park (3D images by )
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