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GENERAL
Origin
:
tropical
Vigour
:
fairly fast
growing
Humidity
:
extremely arid,
very arid, semi-
arid
Propagation :
sowing and
pricking out
Maintenance :
low
CONDITIONS
Urban climate :
resistant
Dessication :
resistant
Stagnant water :
vulnerable
Irrigation
:
low
Salinity/ppm :
moderate (2000
ppm)
Hardiness
:
-9°C
SHAPE
Type
:
tree
Height
:
12 m
Spread
:
16 m
Foliage
:
evergreen
FLOWER
Colour
:
white
Period
:
March - July
Smell
:
scented
FRUIT
Type of fruit :
pod
Fruit size
:
15 cm
Acacia tortilis
ssp.
spirocarpa
is one of four geographically demarcated subspecies of A. tortilis,
which is ubiquitous in arid regions of Africa and widespread in Saudi Arabia, where it is known
as samur. The ssp. spirocarpa is restricted to eastern Africa, with scattered occurrences on sand
dunes and rocky hillsides, on deep alluvial calcareous soils, often indicating a higher water table
or drainage lines. It can also occur on lateritic gravels and saline soils, and will colonise disturbed
sites. This species dominates some savannah communities and provides an important source of
forage. A tall, flat-topped tree, under optimal conditions, it tolerates the severe desert environment
– in Africa, its range often extends into the Sahara desert – although vulnerable until established,
it is hardy to frost, With multiple spreading trunks and the typical silhouette of an inverted
triangle, A. tortilis ssp. spirocarpa is easily recognised by its flattened, spreading crown and hairy
branchlets and pods. Young branchlets and leaves are densely pubescent. It also has spirally
twisted pods, long straight stipular spines and whitish fragrant flowers. Propagation is the same
as A. tortilis ssp. raddiana. It is also planted as a hedge and used for sand dune stabilisation and
shelterbelts. Irrigation is necessary until well-established, but deep watering during the summer
will enhance growth. Low maintenance only, except for pruning to improve appearance, it can be
trained as a standard single leader tree.
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Acacia tortilis
ssp.
spirocarpa,
Mimosaceae
Umbrella Thorn,
samur