A WONDERFUL BUT NEGLECTED TREE SPECIES IN ETHIOPIA – Shiferaw (Cabbage Tree)

Simon Shibru

Forest Genetic Resources Conservation Project

Institute of Biodiversity Conservation and Research

Addis Ababa, Ethiopia

Introduction

How many of us are aware of the fact that a very important tree species, Moringa stenopetala (Baker f.) Cufodontii (1957), is in the process of disappearing from its natural environment in Ethiopia? How many of us ever thought that this species is native to the southern Ethiopia? The writer of this paper is very familiar to it since he was from a small village where the species is widely cultivated and used as a food. However, in spite of his long experience with it the writer has never realized that it is native to southern Ethiopia and also diminishing from time to time from its natural environment until a few days ago when he has got a chance to visit Moringa homepage.

Taxonomy and Distribution

M. stenopetala belongs to family Moringaceae that is represented only by a single genus Moringa. The genus is represented by 14 species to which M. stenopetala belongs. Northeast tropical Africa is a center of endemism plus diversity to the genus (Mark, 1998). Edwards et al., (2000) stated that the taxonomic position of the family is not clear. It has some features similar to those of Brassicaceae and Capparidaceae but the seed structure does not agree with either of the above families. Pollen studies have not provided any other suggestions and recent molecular studies have pointed to a relationship with the Carricaceae. These indicate that the taxonomic position of the family is not yet settled and is open for further studies. Its seed physiology is also not yet studied in the country.

M. stenopetala is a tree 6-10m tall; trunk: more or less 60cm in diameter at breast height; crown: strongly branched sometimes with several branches; thick at base; bark: white to pale gray or silvery, smooth; wood: soft; Leaves: up to 55cm long; Inflorescence: pubescent, dense many flowered panicles ca. 60cm long. For full description refer to Edwards et al., (2000).

The species is known by different vernacular names such as Shiferaw (Am), Aleko, Aluko, Halako (GG), Kallanki (Ben), Telahu (Tse), Haleko, Shelchada (Kon), Haleko (Bur), Haleko (Dh) and Cabbage Tree (Eng).

The Genus follows the distribution pathway from Rajasthan to south West Africa (Africa, Madagascar and parts of Asia, including Arabia and India) (Mark, 1998). The habitat where the genus occur in Ethiopia as summarized from the herbarium sheets of the National herbarium includes: rocky areas along rivers, dry scrub land, Acacia-Commiphora woodland, water courses with some evergreens, Open Acacia-Commiphora bushland on grey alluvial soil and in cultivation around village. M. stenopetala is cultivated in terraced fields, gardens and small towns. The species is found to grow in Keffa, Gamo Gofa, Bale, Sidamo, Borana and Debub Omo zones, and in Konso and Dherashe especial weredas.

The National herbarium has few collections of Moringaceae. The overall collections were represented by 5 species of which the larger part is M. stenopetala. Many of the collections were from Gamo Gofa. There are small seed collections of Moringa species in the Institute of Biodiversity Conservation and Research from Gamo Gofa. However, the viability of these seeds is not yet tested. There is no information documented on M. stenopetala localities in the eastern and northern parts of Ethiopia. It is not clear whether this is due to lack of exploration to the area or really absence of the species in the area.

Origin and Uses

M. stenopetala is often referred to as the African Moringa Tree because it is native only to southern Ethiopia and northern Kenya (Mark, 1998). Though it grows in many other parts of the tropics, it is not as widely known as its close relative, Moringa oleifera but often considered generally more desirable than M. oleifera (Mark, 1998).

It is reported that the edible parts are exceptionally nutritious (Rams, 1994). The leaves are one of the best vegetable foods that can be found in the locality. All parts of the tree except the wood are edible, providing a highly nutritious food for both humans and animals. The flowers are a good nectar source for honey; can be eaten or used to make a tea and the seeds are rich oil sources for cooking and lubricant uses. Many parts of the plant have been used in medicinal preparations. The wood is very soft; useful for paper but makes low-grade firewood and poor charcoal. Attracting attention in recent decades is the use of the dried, crushed seeds as a coagulant (Jahn, 1984). Even very muddy water can be cleared when crushed seeds are added. Solid matter and some bacteria will coagulate and then sink to the bottom of a container. The cleaned water can then be poured off and boiled. Use 100 milligrams (about 1 to 1 ½ seeds) of crushed seed to clean 1 liter of muddy water (Gupta and Chaudhuri, 1992).

Cultivation and Harvesting

It has been reported that M. stenopetala grows wild in elevations between 1,000 and 1,800 m (Mark, 1998) but it will grow as high as 2200m (Pers. obs.) and as low as 300m (herbarium source) in Ethiopia. However, communication with the local people showed that currently this species is known in wild in localized areas in Debub Omo around Turmi. Otherwise it is known as cultivated plant in most places. Studies show that light frosts will do it no harm and freezes, though, may cause it to die back to ground level, where new sprouts may be produced. Full sun is normal, though partial shade is tolerated. It is resistant to dry weather. Optimum light for germination of all Moringa species is half shade.

Seeds should be planted about 2 cm deep in soil that is moist but not too wet. Sprouting occurs normally in 1-2 weeks. It can be allowed to grow for shade (6-15 m), or kept low (about 1-1.5 m) for easier harvesting. M. stenopetala quickly produces a large gray trunk and leaves covered with glistening nectars. It quickly sends out new growth from the trunk when cut, or from the ground when frozen. Living fences can be continually cut back to a few feet. It is an extremely fast-growing tree and continued to grow during the exceptionally long dry season.

Very young whole plants, young leaves and even older leaflets and flowers can be harvested for food. The slender young pods are picked for use like green beans. Seeds of older pods may be shelled from the pods and cooked like green peas. The older flowering branches can be pruned repeatedly to stimulate production of new branch shoots as additional sources of leaves. Moringa is resistant to most pests, though root rot can occur if the soil is too wet.

Cooking and Nutrition

It was reported that Moringa foliage and fruit pods are rich sources of calcium and iron, and good sources of vitamins A, B, and C (when raw) and of protein (including goodly amounts of the sulfur-containing amino acids, methionine and cystine) (Rams, 1994). Both young and older leaves are edible, though older ones are milder and tender. They can be cooked in soups or boiled. Young pods may be also cooked. Immature seeds are often cooked and eaten as a fresh vegetable, while mature seeds can be dried and roasted. The flowers can be cooked or oven-dried and steeped as tea. Dried leaves can be stored as future soup or sauce supplements. Blossoms are edible; they taste like radish. Browning seeds from mature pods that are mashed and placed in boiling water causes an excellent cooking or lubricating oil to float to the surface. The oil preserves well although become rancid with age. Its roots are used as a flavoring and in poultices; and edible oil can be extracted from its seeds. The green pods and surrounding white material can be removed from larger pods and cooked in various ways.

It is reported that M. stenopetala had larger and more appealing in appearance and more palatable leaves, more drought resistance, and larger seeds as compared to the widely known Indian Moringa.

Socioeconomic Values

It is reported that in some parts of Africa there are folk beliefs that Moringa trees planted on graves keep away hyenas and its branches guard against witchcraft. For this reason many families plant Moringa species on and around the graves of their relatives. I believe this way of thought, therefore, has a great contribution to the conservation of the species. In some parts of southern Ethiopia, especially among the konso people, the abundance of Moringa species in the garden or on farmland indicates the social status of the owner among the society. The one with many Moringa tree in the garden or on farmland has a higher social status and also considered rich. In Konso if a man wants to get married and asks a girl to be his wife then the first question that the parents of the would be wife ask to know is how many Moringa trees he has in his garden or farmland. They thought that if the husband has many Moringa trees in his garden or farmland then their daughter will have no problem to feed her babies even when drought happens. For this reason konso people especially young men are encouraged to plant Moringa in their garden as well as on their farmlands. This teaches us that culture by itself has a great role in conservation and sustainable utilization of locally important tree species.

M. stenopetala is planted together with fruit trees in the cropped fields in Konso. Sometimes the trees are also used to provide partial shade for crops like sorghum in the southern Ethiopia. Whole plants have been used as hedges and fences. M. stenopetala can also be planted as a windbreak. As soon as the upper branches of the tree grew broader, the tree can be pruned to stimulate more profuse growth of their lower branches, thus thickening the hedge. Vegetables cultivated behind it profited from this protection. The species can also be grown as an ornamental tree in private gardens and home compounds.

Conservation Status

It is believed by many scholars that the species was introduced to northern Kenya from Dherashe in southern Ethiopia, close to Arbaminch. Its endemicity to a given area implies that it is wild in origin to that particular area. So there is no doubt that M. stenopetala existed in wild in the past in areas where it is common in cultivation. However, in contrast to its original status during which it is known from wild, these days M. stenopetala is mostly known from cultivation in southern Ethiopia around home gardens, home compounds, farmlands, abandoned farmlands and abandoned settlement areas. Though the reasons for its diminishing is not yet investigated, it is very difficult to encounter M. stenopetala from wild in areas where it is common in cultivation such as Gamo Gofa, Konso and Dherashe. The only suspected locality where one may still be able to encounter wild M. stenopetala is in Debub Omo around Turmi village about 780kms south of Addis Ababa. Its wild habitat gets shrink and this eventually will lead to species extinction. In Ethiopia M. stenopetala is nearly endangered in the wild. Therefore, the present writer strongly suggests that something has to be done to restore and conserve this miracle species.

Concluding Remarks

M. stenopetala leaves, pods, and roots are edible; bees love the flowers; and seeds are powdered and used to purify water from muddy rivers. Its parts are actually and potentially useful to extract ingredients of medicinal value. It is truly the mother's best friend in rural parts of southern Ethiopia particularly for mothers of poor family. That is one way they sometimes refer to this tree in Konso and Dherashe where the leaves are cooked and fed to the whole family. The Moringa is also considered as one of God's abundant resources for the struggle against world hunger. However, it is only very small portion of its uses are practiced in Ethiopia. Some people even may not know that it is edible. So much has to be done to promote the species consumption both at local and national level. Awareness should be raised and created on the importance of M. stenopetala and people should be encouraged to plant the species on their home garden and farmlands. This could be at individual level, communal level and even at national level. Establishment of social forestry or communal forestry of the species is worth mentioning to its restoration and conservation. I believe it is one of the most exciting and all-round plants that we have to look very close for its conservation. Conservation and establishment of communal or social forestry of Moringa species may contribute a lot to the national and international efforts to address food shortage in rural parts of the country.

I had planted M. stenopetala in My Parent's garden when I was 15 and now I am 33. Imagine how old my M. stenopetala trees are? My Moringa stenopetala trees are now about 13m tall and my parents still harvest leaves for consumption and also sell leaves in local markets as a source of income to some extent. In fact, I commonly eat the cooked leaves; very tasty and nutritious. I hope I will invite this delicious dish of the M. stenopetala leaves to some of the readers in the near future and then will kindly request to share your enthusiasm for this wonderful tree. I feel that it is one of the best tree species we have to consider for conservation.

If M. stenopetala does not already grow in your locality, you may arrange short trip to southern Ethiopia and can get a reproductive material from the parent trees with out fee and propagate it in your locality.

REFERENCES

1. Edwards. S., Mesfin Tadesse, Sebsebe Demissew and Hedberg I., (2000). Flora of Ethiopia & Eritrea, Volume 2, Part 1: Magnoliaceae to Flacourtiaceae. Addis Ababa, Ethiopia, Uppsal, Sweden 2000.

2. Gupta, A. and Chaudhuri, M., (1992). Domestic water purification for developing countries. J.Water SRT-Aqua, 41 (5) pp 290-298.

3. Jahn,S.A.A.,(1984). Effectiveness of traditional flocculants as primary coagulants and coagulant aids for the treatment of tropical raw water with more than a thousand-fold fluctuation in turbidity. Water Supply, 2(3/4) Special Subject pp 8-10.

4. Mark, E., O., (1998). Research on Applied Uses of Moringa stenopetala

5. Rams, J., (1994). Moringa a highly nutritious vegetable Tree, Tropical Rural and Island/atoll Development Experimental station (TRIADES), Technical Bulletin No. 2. (Source: Internet).