Acacia mearnsii is the (English) Black wattle, or in Swahili Muwati.
The tree is indigenous to Australia and has a wide natural range - from the hot Queensland in the North to cool Tasmania in the South. In Tanzania it is planted at higher elevation, 1,500 - 2, 500m and is planted on many homesteads.
At Lushoto commercial plantations were established for the extraction of tannin, but the operation seems to be in limbo.
Description: A small tree up to 15 m high. The tree often leans because of the shallow root system. Bark is grey and smooth when young becoming black and fissured with splits and curling with age. The split release brown resinous gum. Leaves are feathery and a dull green, leaflets are small. The stalks are10 - 12 cm long and there is a gland at the base. Flowers are pale yellow, small round heads on branched stalks - sweetly scented. Fruit are pods, either straight or or bent 5 - 10 cm jointed between the seeds. The pods dry to a dull brown colour.
Uses: Very good firewood and charcoal. Poles, posts and tool handles. Good bee forage (pollen), soil conservation, nitrogen fixation, fibre (bark), gum, tannin.
Propagation: There are 50 - 80 000 seeds per kg, they are black and hard and store well.
Germination is >80% if hot water soaked or exposed to fire. Nicking is a sure method but is fiddly because the seed is small.
The tree grows well in nursery pots and performs well at outplanting - responds to super phosphate.
I have grown this species in the NZ nursery as it is used as a chipping crop. However it can become a pest and will even survive amongst P. radiata plantings.
My opinion is that green trees are always good in Tanzania and climate will control its spread. Fuelwood is in short supply so controlling its spread. It does not have thorns.
Thin strips of fresh bark (from young trees) make good cordage - especially in making wattle and daub buildings - drying to be very firm.
The tree grows quickly but tends to be short-lived.
Termites damage the tree from time to time and sometimes there are fungal attacks.
However the tree is useful as cash crop on small scale farms.
At Lushoto commercial plantations were established for the extraction of tannin, but the operation seems to be in limbo.
Description: A small tree up to 15 m high. The tree often leans because of the shallow root system. Bark is grey and smooth when young becoming black and fissured with splits and curling with age. The split release brown resinous gum. Leaves are feathery and a dull green, leaflets are small. The stalks are10 - 12 cm long and there is a gland at the base. Flowers are pale yellow, small round heads on branched stalks - sweetly scented. Fruit are pods, either straight or or bent 5 - 10 cm jointed between the seeds. The pods dry to a dull brown colour.
Uses: Very good firewood and charcoal. Poles, posts and tool handles. Good bee forage (pollen), soil conservation, nitrogen fixation, fibre (bark), gum, tannin.
Propagation: There are 50 - 80 000 seeds per kg, they are black and hard and store well.
Germination is >80% if hot water soaked or exposed to fire. Nicking is a sure method but is fiddly because the seed is small.
The tree grows well in nursery pots and performs well at outplanting - responds to super phosphate.
I have grown this species in the NZ nursery as it is used as a chipping crop. However it can become a pest and will even survive amongst P. radiata plantings.
My opinion is that green trees are always good in Tanzania and climate will control its spread. Fuelwood is in short supply so controlling its spread. It does not have thorns.
Thin strips of fresh bark (from young trees) make good cordage - especially in making wattle and daub buildings - drying to be very firm.
The tree grows quickly but tends to be short-lived.
Termites damage the tree from time to time and sometimes there are fungal attacks.
However the tree is useful as cash crop on small scale farms.
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