Agroforestree Database

Local names:
 Afrikaans (borasusspalm), Amharic (zembaba), Arabic (deleib,delieb), Bemba (kambili,kakoma,chibangalala), English (fan palm,deleb palm,African fan palm,palmyra palm,borassus palm,ron palm), French (palmier ronier,rônier), Fula (dubbe,dubbi), German (palm

Borassus aethiopum is an unbranched palm growing up to 20 m tall, characterized by a crown up to 8 m wide; young palms are covered with dry leaf stalks, showing gradually fading leaf scars; trees over 25 years old have a swelling of the trunk at 12-15 m above the ground (at 2/3 of the height); bark is pale grey in older palms and is more or less smooth.

Leaves very large, fan shaped, bluish-green, 15-30, up to 3.5 m long, including petiole which is marked with sharp, black thorns; leaflets symmetric at the base.

Flowers dioecious, yellowish; male flowers clustered in a branched spadix, 0.8-1.8 m long. Female flowers with unbranched and shorter spadix, 1.3-2.6 m long.

The fruit a large drupe, diameter about 15 cm, ovoid, orange to brown when ripe; fibrous pulp contains 3 woody kernels with an albumen that becomes hard when ripe.

This genus is probably the only tropical species that bears a generic name so old that its meaning has been lost in time. The name ‘flabellifer’ means ‘fan shaped’ and refers to the shape of the leaves.

Ecology

Distributed in the Guineo-Congolian and Sudanian savannahs, B. aethiopum is abundant and characteristic in all types of savannah of the region, occurring at low altitudes along rivers and in coastal woodlands. It can tolerate high temperatures and will grow in areas with rainfall less than 500 mm/yr if the groundwater table is high. It is often in dense stands. The palm can serve as an excellent firebreak, especially in the arid regions of West Africa, which are prone to wildfires.

Native range
Benin, Burkina Faso, Congo, Cote d'Ivoire, Democratic Republic of Congo, Ethiopia, Gambia, Ghana, Guinea, Guinea-Bissau, Kenya, Liberia, Mali, Mozambique, Nigeria, Senegal, Sierra Leone, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia, Zimbabwe

Tree management

Growth of the palms depends very much on site conditions. Three phases of growth are recognized. The 1st phase takes 6-8 years and involves leaf development, in which about 20 leaves grow in a wide crown (about 3 x 3 m). There is very little upward growth then. The 2nd phase involves rapid growth of the trunk above the ground and takes place from the 8th to about the 20th year. The bark of the tree will still be rough and have many leafstalks. The 3rd phase involves flowering and shedding of leafstalks. The trunk becomes smooth and swellings appear on it.

Little care is required if palms are established on a good site. However, young leaves should be harvested only under very controlled conditions if the palm is to grow properly. Rotation periods depend on the site but can be 60-140 years.

For palm wine tapping, the terminal bud of the tree is cut and the dripping sap of the phloem is collected in a receptacle. The cut is renewed twice every day for 3-4 weeks until the tree is exhausted and dies. During this period B. aethiopum can yield about 200-500 litres of sap. Overtapping of the tree for its sap has made the tree rare.

Seeds have a very short period of viability and should be sown directly after they are removed from the pulp. It has been suggested that this species may not show recalcitrant seed storage behaviour. There are 2-3 seeds/kg.

Distributed in the Guineo-Congolian and Sudanian savannahs, B. aethiopum is abundant and characteristic in all types of savannah of the region, occurring at low altitudes along rivers and in coastal woodlands. It can tolerate high temperatures and will grow in areas with rainfall less than 500 mm/yr if the groundwater table is high. It is often in dense stands. The palm can serve as an excellent firebreak, especially in the arid regions of West Africa, which are prone to wildfires.

The seed can be sown without removing the surrounding pulp. Germination takes 1 month. Pretreatment is not necessary. However, removal of the seed coat by excision breaks the long and unpredictable dormancy and results in a higher germination percentage. The poor germination is a severe handicap in agricultural practice. Another agronomic drawback is that once it sprouts, the seedling cannot be transplanted or planted out.

  The fruits have a large, fibrous pulp (around 500 g each) that smells strongly of therbenthine. They are consumed raw or cooked, preferably with rice. The kernels contain an albumen, which before ripening is sweet and refreshing. The immature seeds can be eaten and contain a sweet jelly that has a refreshing taste. The mature seeds can be buried in pits and allowed to germinate, and the shoots are said to be a delicacy. Fresh sap is used as a yeast or made into vinegar.

Fruits and young leaves are sometimes browsed for fodder.

Apiculture:  In Uganda, B. aethiopum trees are cut and hollowed out to make beehives.

Firewood and charcoal can be obtained from B. aethiopum.

Fibre:  The fibre extracted from the base of the leaf stalk has valuable qualities of resistance to chemicals, termites and water. Young leaves, before unfolding, can be split into strips and woven into thin mats, baskets and other household objects. The leaf midribs are used to make brooms, fish traps and nets. The leafstalk endings can be soaked in water to provide fibres that are used as sponges or filters.

Timber:  The wood is hard, moderately heavy and brown with black fibres. The strong trunks are very resistant to decay and to insects, especially termites. They are frequently used as posts and for construction of bridges. The boards cut from the trunks are used for the construction of shower cabins. The trunk and leaf stalks are used to make stakes. In Mozambique, people use the trees to make dugout canoes. Other products include door frames, roof materials, tool handles and drums.

Shade or shelter:  Mature leaves are used for roofing.

Lipids:  Oil can be extracted from the fruit and pulp.

Medicine:  In traditional medicine, palm wine is a component of several aphrodisiac preparations. The flowers help against aphonia, and young leaves are used to stop haemorrhage.

Ornamental:  B. aethiopum is an attractive palm and has been planted for amenity purposes.

Alcohol:  B. aethiopum is particularly appreciated because of its sap, tapped from flower spikes, which ferments to palm wine, ‘kue za’, the traditional beverage of the Baoulé of Cote d’Ivoire. Palm wine can be distilled to form ‘koutoukou’, but this spir