Agriculture Reference
In-Depth Information
fibrous, exuding a nearly colorless gum; there is a short bole and stout branchlets. The leaves have
a slender glabrous common stalk 10-22 cm long, compound, alternate, and tufted at the ends of
the branchlets. The leaflets are opposite or nearly opposite, 5-10 pairs with an off-terminal leaflet,
elliptic to obovate, 2-5 cm wide, and apex more or less rounded but with a very short, sharp tip; the
base is cuneate, with margins usually entire, dentate on young and coppice undergrowth, glaucous,
pale green, with venation obscure, subsessile. The flowers appear when the tree is leafless and are
dioecious, greenish white or reddish; subtending bracts are reddish, broadly ovate, and conspicuous
at first. The male flowers have 12 or more stamens and occur as solitary, erect spikes; the female
flowers occur 2 or 3 together, and pedicels are stout, 2-2.5 long, with sepals purple-red. The pet-
als are recurved, green with purple-red tips. The fruit occurs as a pale yellow drupe, subglobose,
3-4 cm long, 2.5-3.5 cm in diameter, and containing 2-3 seeds surrounded by a leathery rind and
fibrous pulp. 33
Habitat and Distribution — The plant occurs in the drier savannas of northern tropical Africa,
usually on sandy soils and sometimes on lateritic or stony soils. It can thrive in areas with rainfall
as low as 300 mm per annum; in higher-rainfall areas, 450-800 mm, the tree is often conspicuous
as an emergent tree through the canopy of the neighboring savanna trees. It is distributed in the
savanna belt between Senegal and Ethiopia and in drier areas of southern Africa. It has been located
in Togo, Mali, Guinea Bissau, Gambia, Ivory Coast, Burkina Faso, Ghana, Togo, Benin, Niger,
Nigeria, Chad, Sudan, and Uganda.
Ethnomedicinal Uses — The main use of the plant in traditional medicine is for the treatment
of diabetes. The Hausas use a cold infusion of the stem bark for the treatment of dysentery. And
in Senegal, the leaves and root barks are employed with other plants in the preparation of plaster
as a remedy against snake- and scorpion bites. An infusion of the bark is used to wash infants as a
treatment for malaria or inflammation.959 959 The eastern and southern African species S. caffra Sond
is employed extensively in traditional medicine and has been used for the treatment of dysentery,
diarrhea, and malaria and as a general tonic. S. birrea is administered by the Venda in the form of
the powdered bark to expectant mothers to regulate the sex of the child: Bark from a male tree is
dispensed for a boy and bark from a female tree for a girl. 79 The plant is used in religious rituals by
the Shagana in divining dice. Both species yield pleasant-tasting fruits that are often fermented to
give a refreshing drink.
The marula fruits are highly aromatic and can be eaten fresh or used in making juices, jams, and
alcoholic beverages, such as Amarula and Tombo.
Constituents — The plant has been shown to contain flavonoids, catechins, and gallotannins.
The pulp and kernels of the fruit contain glucosides, amino acids (especially glutamic acid and
arginine), and lipids (mostly oleic [60%], myristic, and stearic acid). The fruits are rich in vitamin
C. The nutritional profile of the pit has been evaluated, and it contained relatively large amounts
of copper (24.8 mg/g dry weight), magnesium (4210 mg/g dry weight), and zinc (62.4 mg/g dry
weight). The protein content of the pit was high (36.4% of dry weight); however, the protein fraction
contained relatively low proportions of leucine, phenylalanine, lysine, and threonine. Fatty acids
accounted for 47 mg/g dry weight of the pit, two-thirds of which was due to oleic acid. The essen-
tial fatty acid linoleic acid was present (24.5 mg/g dry weight), but the other essential fatty acid,
α-linolenic acid, was absent. 961
Pharmacological Studies — Extract of the plant has been shown to possess hypoglycemic
action following intraperitoneal or oral administration. 960-962 The activity is believed to include
peripheral stimulation of glucose uptake and metabolism. The anti-inflammatory effects of the
aqueous and methanolic stem bark extracts (500 mg/kg p.o.) have been examined on rat paw
edema induced by subplantar injections of fresh egg albumin (0.5 ml/kg). Acetylsalicylic acid
(ASA, 100 mg/kg p.o.) was used as the reference anti-inflammatory agent for comparison. Both
the aqueous and methanolic stem bark extracts of S. birrea (500 mg/kg p.o.) progressively and
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