Maesopsis eminii (PROSEA)
Maesopsis eminii Engler
- Protologue: Pflanzenw. Ost-Afr. C: 255 (1895).
- Family: Rhamnaceae
- Chromosome number: 2n= 18
- Maesopsis berchemioides (Pierre) A. Chev. (1917).
- Umbrella tree, musizi (standard trade name) (En).
- Musizi (Fr)
- Indonesia: kayu afrika.
Origin and geographic distribution
M. eminii occurs naturally between 6°S and 8°N in tropical Africa along the Gulf of Guinea (incuding Sao Tomé) from Liberia to Angola and through Zaire, southern Sudan and Uganda to Kenya and Tanzania. It was introduced into Java in the 1920s and is cultivated there and in Sumatra and Kalimantan. From Java, it was introduced into Peninsular Malaysia in 1952. Plantations of M. eminii have been established in Africa, India, Indonesia, Malaysia and Fiji, while it has been introduced for testing in Costa Rica, Hawaii, Puerto Rico, the Solomon Islands and Western Samoa.
In Africa M. eminii is commonly retained in home gardens for shade, fuel and timber, while the leaves are used as fodder. In Africa and India it is often planted as a shade tree in coffee, tea and cardamom plantations, in Zaire also to shade cocoa trees. Because of its fast growth, it is widely planted for fuelwood, although its light wood is not an ideal fuel. In Java it is commonly planted for this purpose along roads and field boundaries.
Musizi is a good general purpose timber for indoor construction, for joinery, boxes, furniture and millwork, corestock for plywood and particle board. In Uganda, M. eminii is used for enrichment planting. The bark is used for roofing and for medicinal purposes in Africa (a decoction is diuretic and purgative).
M. eminii is a common ornamental and shade tree planted along roads.
The heartwood is yellowish green when fresh, quickly turning golden to dark brown, the sapwood is white. The heartwood is light with a density of 380-480 kg/m3, soft, moderately strong and medium to coarse in texture. It dries fairly rapidly with some warp but little checking. Logs have a tendency to split during felling and storage. Timber is easy to saw and works well with machinery, but is difficult to finish. The grain is interlocked. Wood is attacked by termites and is liable to fungal decay, but is highly absorbent and easily treated with preservatives.
The wood of M. eminii yields about 50% screened pulp for paper-making, comparable in tearing strength, tensile strength, and bursting strength to commonly used temperate hardwood species.
Analyses of seed from Karnataka, India indicate that the seed of M. eminii contains 40-45% of an edible oil, the main components of which are stearic acid (27%), oleic acid (47%), and linoleic acid (15%). Digestibility of the leaves by livestock is excellent and only slightly reduced by heating. The leaves have a dry matter content of 35% and contain per 100 g dry matter: crude protein 26 g, ether extract 3.6 g, ash 5 g, neutral detergent fibre 20 g, lignin 5.4 g, total phenols 2.4 g, tannin (vanilline-HCl method) 5.6 g, tannin (pepsin precipitation method) 0.9 g. The weight of 1000 seeds is up to 200 g.
- Unarmed, evergreen to deciduous tree, 15-25(-45) m tall with an open, spreading crown. Bole exceptionally straight, cylindrical, up to 15 m tall and 50(-180) cm in diameter; buttresses small or absent; bark pale grey to grey-brown or almost white, smooth or with deep, vertical, often twisted furrows; slash red outside, yellow near the wood. Branchlets with patent short hairs.
- Leaves mostly subopposite, simple, glandular-serrulate; stipules subulate, 2-6 mm long, puberulent, caducous; petiole 6-12 mm long, puberulent to glabrescent; blade ovate-elliptical to oblong-ovate, 7-14 cm × 2.5-6 cm, lustrous above, paler beneath, glabrous except when young, base rounded to subcordate, apex acuminate, margins with rounded teeth 0.3-5 mm long.
- Inflorescence a many flowered, axillary cyme, 1-5 cm long; peduncle 4-25 mm long.
- Flowers bisexual, 5-merous, yellowish-green; pedicel 1-3(-6) mm long; sepals deltoid, 2-6 mm long; petals very strongly concave-convex, hiding the anthers, not clawed; anthers subsessile; style short, dilated; stigma stellately 10-lobed; style and stigma persistent in fruit.
- Fruit an obovoid drupe, 20-35 mm × 10-18 mm, turning from green to yellow to purple-black when maturing; mesocarp floury, cream-coloured, endocarp creamy-brown.
Growth and development
M. eminii grows rapidly at 1-3 m per year in height and 1.5-5.5 cm per year in diameter. In Malaysia, it has reached a height of 20 m in 6 years. It flowers from February to May and from August to September in Peninsular Malaysia. Seeds ripen about 2 months after flowering. They are dispersed by birds (especially hornbills in Africa), bats, rodents and monkeys. M. eminii is remarkably long lived for a pioneer species attaining over 150 years.
Other botanical information
Maesopsis A. Engler is a monospecific genus, rather isolated in the Rhamnaceae because of the structure of its wood, its number of chromosomes, its protogynous flowers and the morphology of its ovary and style.
M. eminii is sometimes divided into 2 subspecies: subsp. eminii (occurring in East Africa and e.g. in South-East Asia; very large trees with large prominent glandular teeth on the leaves), and subsp. berchemioides (Pierre) N. Hallé (occurring from Nigeria to Angola; smaller trees with glandular teeth on the leaves much less prominent, about 1-1.5 mm long).
In Africa, M. eminii occurs in association with many other species from lowland tropical rain forest to savanna, extending into submontane forest up to 1500 m altitude, in Rwanda even up to 1800 m. In Java and Malaysia it is mostly planted in the lowland, but it is more vigorous at 600-900 m altitude. It prefers a mean annual rainfall of at least 1200-1300 mm and tolerates a dry season of up to 2 months. In its habitat the mean annual temperature ranges from 22-27 °C, the mean maximum temperature of the hottest month from 26-32 °C, the mean minimum temperature of the coldest month from 16-24 °C. It is very light demanding.
M. eminii grows best on deep fertile soils. It tolerates a wide range of soils, from medium to light and from neutral to very acid, but it does not tolerate waterlogging. In Malaysia, good growth was obtained on alluvial and sedimentary, granite-derived soils.
It was introduced first in German colonial times in the Usambara mountains in eastern Tanzania, then again in the 1930s and 1960s and has rapidly invaded submontane rain forest, to become the dominant species there.
Propagation and planting
M. eminii is mostly propagated by seed obtained from fresh ripe fruit, after the pericarp has been mechanically removed and the seed has been dried for several days. To improve germination, seed may be soaked in water for 1-2 days, or in concentrated (20 N) sulphuric acid for 20 minutes. Fresh seed has yielded over 90% germination, but viability decreases rapidly after 3 months. Germination generally takes 2-6 weeks, but has been reported to require 100-200 days. Direct seeding is feasible. Because of the strong development of the taproot, polybag nurseries are preferred to raised beds. Seedlings attain plantable size after 2-24 months. Potted striplings and stumps have given good results. Seedling survival rates of 57-84% are reported from Malaysia.
Thinning is required after the 5th year to allow a proper crown/stem ratio to develop. For optimal growth, a density of about 125 trees/ha has been calculated in Malaysia. Established plantations may be coppiced. M. eminii is self-pruning. It has been proposed as an alternative for Paraserianthes falcataria (L.) Nielsen, where the latter is affected by Xystrocera wood borers. Rotations in M. eminii plantations are kept at 30-40 years, since older trees are often wind-thrown. Rotations are about 8 years for fuelwood, poles and pulp production. In plantations M. eminii competes well with weeds but cannot suppress Imperata grass.
In agroforestry experiments in Rwanda its growth was not affected by any of the associated crops, but yields of the latter were strongly reduced. Common bean (Phaseolus vulgaris L.) did best, yielding about 60% of the unshaded controls.
Diseases and pests
Poorly growing trees of M. eminii on soils of low fertility or with impeded drainage are prone to canker (in Uganda caused by Fusarium solani). Fungal rot may occur during the often long germination period. A bacterial blight may cause damage on poorly drained sites in Malaysia. It is relatively free of pests in South-East Asia, only debarking by squirrels has been reported to cause damage in Malaysia.
Average annual increments of 8-20 m3/ha are common, but can be as high as 33 m3. In Malaysia trees planted from seed from Java and Ghana reached harvestable size after 5-8 years. After 5 years at a density of 850 trees/ha the timber yield was about 175 m3/ha; after 9.5 years the density was reduced in 2 thinnings to 125 trees/ha, while the timber yield was about 300 m3/ha.
Genetic resources and breeding
M. eminii appears to be a genetically broad species, reflected e.g. in a significant difference in size between East and West African provenances, the former being much taller. In Malaysia collections of genetic resources are maintained by the Forest Research Institute of Malaysia in four localities in Perak, Kedah and Sarawak.
Because M. eminii can easily be propagated by stumps, requiring little attention after planting and yielding relatively well on poor soils, it may continue to play a role in the reclamation of degraded land and enrichment planting. Given its open crown and long lifespan, M. eminii could also continue to play a role as a shade tree for estate crops.
- Binggeli, P. & Hamilton, A.C., 1993. Biological invasion by Maesopsis eminii in the East Usambara forests, Tanzania. Opera Botanica 121: 229-235.
- Egli, A.E., 1994. Einfluss ausgewählter Standortsfaktoren in Abhängigkeit von zehn nicht Stickstoff fixierenden Baumarten auf die Ertragsbildung wichtiger Feldfrüchte unter agroforstlichen Anbaubedingungen. Ein Beispiel aus Butare/Rwanda (Ost-Zentralafrika) [The effect of interactions of selected environmental conditions with ten non-nitrogen-fixing species of trees on the development of yield of important field crops grown under agroforestry conditions. An example from Butare/Rwanda (Eastern Central Africa)]. Forstwissenschaftliche Beiträge der Professur Forstpolitik und Forstökonomie 1994/13. Department Wald- und Holzforschung, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland. 206 pp.
- Johnston, M.C., 1972. Rhamnaceae. In: Milne-Redhead, E. & Polhill, R.M. (Editors): Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United kingdom. pp. 36-38.
- Mahyuddin, P., Little, D.A. & Lowry, J.B., 1988. Drying treatment drastically affects feed evaluation and feed quality with certain tropical forage species. Animal Feed Science and Technology 22: 69-78.
- Palmer, E.R., Gibbs, J.A. & Dutta, A.P., 1983. Pulping characteristics of hardwood species growing in plantations in Fiji. TPI Report L64. Tropical Products Institute, London, United Kingdom. 43 pp.
- Sandrasegaran, K., 1966. Optimum planting distances and crop densities of ten exotic species utilizing triangular spacing based on a consideration of crown diameter to stem diameter relationship. Research Pamphlet No 51. Forest Research Institute, Kepong, Malaysia. 44 pp.
- Smiet, A.C., 1990. Agro-forestry and fuelwood in Java. Environmental Conservation 17: 235-238.
- Widiarti, A. & Alrasjid, H., 1987. Penanaman introduksi jenis pohon kayu bakar di lahan kritis Paseh dan Kadipaten [Introduction of fuelwood tree species on degraded lands in Paseh and Kadipaten areas]. Buletin Penelitian Hutan 488: 1-17.
- H.G. Schabel & A. Latiff