Gum arabic tree

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Gum arabic tree
Acacia senegal - Koehler – s Medizinal-Pflanzen-004.jpg

Gum arabic tree ( Senegalia senegal )

Systematics
Order : Fabales (Fabales)
Family : Legumes (Fabaceae)
Subfamily : Mimosa family (Mimosoideae)
Tribe : Acacieae
Genre : Senegalia
Type : Gum arabic tree
Scientific name
Senegalia Senegal
( L. ) Britton

The gum arabic tree ( Senegalia senegal (L.) Britton, syn .: Acacia senegal (L.) Willd. ), Also called Senegal acacia or rarely Verek acacia , is a species of the genus Senegalia in the subfamily of the mimosa family (Mimosoideae) within the family of legumes (Fabaceae). It is widespread in Africa with three varieties.

description

Senegalia senegal grows as a semi - evergreen , drought-resistant shrub or small tree and reaches heights of 2 to 8, or 10–15 meters. The umbrella-shaped crown is strongly branched and is formed by many upright branches on which there are (barely) internodal thorns , often in groups of three or individually, and gray-green leaves. It forms a deep tap root . The bark is grayish to brownish and with age it becomes darker and scaly to flaky or cracked.

The alternate, stalked and short leaves are bipinnate, with more or less hairy 1st and 2nd order rhachis. The more or less hairy petiole is up to 2 centimeters long. There are about 3-11 pairs of leaflets with about 7-25 pairs of small, leathery, slightly hairy to bald leaflets . Spines can sometimes appear on the rachis . The stipules are small and mostly absent or fall off early. There may be glands on the leaves.

The cylindrical and multi-flowered, spiked inflorescences contain yellow or cream-colored, hermaphrodite and fragrant, five-fold flowers with a double inflorescence . There are many (100-200) long, short overgrown at the base of stamens and a short-stalked, upper permanent ovary with long stylus provided.

The flat, brown, about 5–19 centimeters long, 1.5–3 centimeters wide, more or less hairy, somewhat veined, mostly opening and mostly pointed legumes contain 3 to 8 red-brown, shiny and smooth, 8–12 millimeters long, flat, rounded seeds. The indented pleurogram is U-shaped.

Occurrence

Senegalia senegal often grows in savannahs and only needs between 100 and 800 mm of annual precipitation , usually 300 to 400 mm, and can withstand dry periods of 8 to 11 months. Sandy or slightly loamy soils are preferred in the semi-arid Sahel zone , especially in West Africa and the western part of Sudan .

Systematics and distribution

It was first published in 1753 by the Swedish botanist Carl von Linné under the name ( Basionym ) Mimosa senegal in Species Plantarum , 1, p. 521. The German botanist Carl Ludwig Willdenow named this species Acacia senegal in Species Plantarum , 4, 2, p 1077. Nathaniel Lord Britton publishes the name Senegalia senegal in Scientific Survey of Porto Rico and the Virgin Islands , 6, 1930, p. 538 . Senegalia senegal is accordingly B. Kyalangalilwa & JS Boatwright: Phylogenetic position and revised classification of Acacia sl (Fabaceae: Mimosoideae) in Africa, including new combinations in Vachellia and Senegalia , In: Botanical journal of the Linnean Society , Volume 172, 2013, p 510 the currently accepted botanical name. Other synonyms are: Acacia verek Guill. & Perr. and many others.

Three varieties are accepted within the species Senegalia senegal :

use

1784 in Senegal - "The Moors collect gumi ..."

Gum arabic is extracted from the tree and sweated out. To increase the yield, cut the trunk and branches of the tree after the rainy season. With little effort, a relatively high sales revenue is achieved. The tree is also suitable for controlling desertification and wind erosion, with its widely branched flat roots it is suitable for fixing sand dunes. Traditionally, planting in Sudan takes place in chronological order after the cultivation of sorghum , peanuts , sesame and karkadeh , which guarantees soil fertility recovery for 10 to 15 years.

The yield of gum arabic depends on the sufficient water supply in the soil. Studies in western Sudan have shown that the cultivation of Senegalia Senegal in low density together with sorghum or karkadeh has proven to be beneficial because it helps to reduce poverty and provide food for the local population. The yield of rubber sap per tree with the same planting distance could be increased especially in connection with the cultivation of Karkadeh.

The seeds can be eaten, an oil can also be obtained and also a coloring agent. The roots can be used medicinally, or fiber can be obtained from them.

The heavy and hard wood is used in house building, for fences and as fuel. In addition to the “Arabian” or “acacia gum”, the bark is rich in tannin and is therefore used in African folk medicine for its astringent and expectorant properties.

literature

  • CW Fagg, GE Allison: Acacia senegal and the gum arabic trade: monograph and annotated bibliography. Tropical Forestry Papers No. 42, University of Oxford, 2004, ISBN 0-85074-157-2 , online , (PDF; 68.8 MB).

Individual evidence

  1. ↑ a b c Senegalia Senegal in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved August 29, 2013.
  2. ^ MA Eisa: Acacia senegal (Gum Arabic Tree): Present Role and Need for Future Conservation / Sudan. German Tropical Day, 7. – 9. October 2008, University of Hohenheim (PDF; 164 kB).
  3. ↑ Abdalla Gaafar Mohamed: Improvement of Traditional Acacia Senegal Agroforestry. Ecophysiological characteristics as indicators for tree-crop interaction. University of Helsinki, 2005 (PDF), pp. 3, 23, 47.

Web links

Commons : Gum arabic tree ( Senegalia senegal )  - Album with pictures, videos and audio files