Xylocarpus granatum (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Vegetable oil
Dye / tannin
Medicinal
Timber
Fuel
Ornamental

distribution in Africa (wild)

1, flowering branch; 2, female flower; 3, fruit. Source PROSEA

flowering branch (A field guide to Kenyan mangroves)

fruiting tree (Mangroves of India)

leaf (A field guide to Kenyan mangroves)

flowers (A field guide to Kenyan mangroves)

flowers (Mangroves of India)

Xylocarpus granatum J.König

Protologue: Naturforscher 20: 2 (1784).

Family: Meliaceae

Chromosome number: 2n = 42, 52, 58

Synonyms

• Carapa obovata Blume (1825),
• Xylocarpus obovatus (Blume) A.Juss. (1830),
• Carapa granatum (J.König) Alston (1931).

Vernacular names

• Cannonball mangrove (En).
• Mangalbola de canhão (Po).
• Mkomafi, mtifi (Sw).

Origin and geographic distribution

Xylocarpus granatum is widely distributed in coastal regions of the Old World tropics, from East Africa and Madagascar through tropical Asia, to tropical Australia and Polynesia.

Uses

The bark of the bole of Xylocarpus granatum is rich in tannin and is used for tanning heavy hides into sole leather and other heavy leather, and for toughening and preserving fishing nets. It is sometimes used to dye cloth brownish or reddish. The wood is a good mahogany-like timber, but as the trunk is usually crooked and hollow, long straight pieces cannot be cut. It is used in boat building, and for nails, house-posts, wood carvings, tool handles and furniture, but it is not resistant to termites. In India the wood is found suitable for second grade pencils. It can also be used as firewood, but it burns quickly and produces great heat, which is why other sources are preferred. The oil extracted from seeds has been used as an illuminant and as hair oil. The astringent bark has some medicinal uses. It is used to treat dysentery, diarrhoea and other abdominal troubles, and as a febrifuge. The fruit is used in India to treat swellings of the breast and elephantiasis. Burned seeds have been used mixed with sulphur and coconut oil against itchy skin. On Mafia Island (Tanzania) a decoction of the crushed fruits is drunk as an aphrodisiac.

Production and international trade

The bark is used only locally for tanning and dyeing purposes because natural supply is not abundant. Xylocarpus granatum is usually not found in pure stands and its bark is thin. The wood is of local importance only.

Properties

Most parts of the plant contain tannin: bark, wood, leaves and fruits. However, the bark of mature trees is richest in tannin, containing 20–34% on dry matter base. The tannin penetrates hides rapidly and produces a reddish brown, tough leather, but nothing is known about its composition. The seeds yield 1–2% of oil. The wood is reported to contain 0.1% gedunin, a limonoid, with antimalarial activity that is found in many other Meliaceae species, e.g. neem (Azadirachta indica A.Juss.). In Malaysia an aqueous seed extract showed significant in-vitro antifilarial activity against Brugia malayi. The wood is moderately heavy with a density of 630–790 kg/m² at 15% moisture content, and moderately hard and durable. The heartwood is reddish, darkening to a deep warm brown on exposure, usually sharply demarcated from the narrow, buff-coloured to silver-grey sapwood. The grain is straight or slightly interlocked, texture fine and even. The wood shrinks little and is usually easy to work and finish, and it takes a high polish. The pulping and paper making properties of Xylocarpus granatum are rated as poor.

Description

• Small to medium-sized tree up to 15(–20) m tall; bole often of poor form, up to 90 cm in diameter, with thin, branched ribbon-like surface roots; bark thin, smooth, scaly with irregular flakes, whitish to yellow-brown, inner bark reddish pink.
• Leaves alternate, paripinnately compound, with 1–2(–3) pairs of leaflets; stipules absent; petiole and rachis up to 12 cm long; petiolules 2–11 mm long, thickened; leaflets elliptical or obovate, 4–12 cm × 2–6 cm, base cuneate, apex rounded, entire, leathery.
• Inflorescence an axillary thyrse up to 6 cm long, often forked with indistinct main axis.
• Flowers functionally unisexual, regular, 4-merous; pedicel 3–9 mm long, thickened near the calyx; calyx lobed to about the middle, lobes 1–3 mm long; petals free, oblong, 3.5–6.5 mm × 2–3 mm, creamy-white or pinkish; stamens 8, united into a tube 2–3.5 mm in diameter; disk well developed, 8-lobed, red; ovary superior, 4-celled, style short and thick, stigma large.
• Fruit a globose, pendulous, woody capsule 12–25 cm in diameter, weighing up to 3 kg, tardily dehiscing by 4 valves from apex, 6–20-seeded.
• Seeds irregularly tetrahedral, up to 6 cm long, brown, with a corky seedcoat.
• Seedling with hypogeal germination, initially with scale leaves, first leaves simple.

Other botanical information

Xylocarpus is a small genus, comprising 3 species which are very similar, and consequently have often been confused. In tropical Africa and the African Indian Ocean islands only 2 species are found: Xylocarpus granatum and Xylocarpus rumphii (Kostel.) Mabb. In most African floras Xylocarpus rumphii is erroneously named Xylocarpus moluccensis (Lam.) M.Roem., which in fact is the third species and restricted to tropical Asia and Australia and not in Africa. Xylocarpus rumphii is not a mangrove species, growing on sandy and rocky coasts and has no ribbon-like surface roots. It has ovate, slightly acuminate leaflets and fruits of 6–8 cm in diameter. Its bark is rough and longitudinally fissured, and can also be used for tanning purposes, although in Africa the species is less common than Xylocarpus granatum. The wood of Xylocarpus rumphii is occasionally used, e.g. for masts and furniture in Kenya.

Anatomy

Wood-anatomical description:

– Macroscopic characters:

Heartwood reddish, darkening to a deep warm brown on exposure, usually sharply demarcated from the narrow, buff-coloured to silver-grey sapwood. Grain straight or slightly interlocked. Texture fine and even. Wood with darker streaks producing attractive watered-silk figure on tangential surfaces. Growth rings distinct or indistinct.

Growth and development

Trees are usually evergreen, even in seasonal climates, but are sometimes deciduous. They sucker basally when they are damaged, and depauperate plants may develop several trunks. Growth is according to Rauh’s architectural model, characterized by a monopodial trunk which grows rhythmically and develops tiers of branches. Each new flush is marked by a few scales followed by pinnate leaves. Flowering is usually in the rainy season. Flowers are functionally unisexual, male flowers having a non-functional, rather slender ovary, female flowers having non-functional stamens either never dehiscent or with sterile pollen. It has been observed that certain individuals, although flowering profusely, never produce fruit; this suggests that dioecism sometimes occurs. Flowers are probably pollinated by short-tongued insects like bees. Usually only one fruit develops per inflorescence. The corky testa of the seed represents an adaption to dispersal by water, and seeds may start to germinate while still floating. Germinated seeds do not become readily established in the mud but are often washed away with the tide. This may contribute to the prominence of the species at higher elevations in a mangrove.

Ecology

Xylocarpus granatum is a mangrove plant, found in tidal mud of mangrove swamps, especially towards their upper limits. It tolerates a salinity of 0.1–3%.

Propagation and planting

In natural conditions, the seeds of Xylocarpus granatum float just below the water surface and are dispersed by ocean currents. Seed viability decreases rapidly upon storage. Seeds should be sown with the convex side upwards. They show about 70% germination in 1–2.5 months. Seedlings can attain 50 cm height in 3 months. Direct sowing has been successfully applied in a trial plantation of Xylocarpus granatum at 1 m × 1 m. Xylocarpus is a moderate light demander, particularly enduring shade when young. A decrease in freshwater supply during the dry season can result in high mortality.

Management

In mangrove forests, Rhizophora and Bruguiera species are usually considered more valuable than Xylocarpus which is sometimes cut down to promote growth of the other species. Large Xylocarpus granatum trees are often crooked and gnarled, and the bole is hollow, which makes it difficult to obtain large timber sizes.

Harvesting

The bark is peeled from the tree for use in local tanneries. The tree recovers easily from the peeling.

Handling after harvest

Usually the bark is directly used in the tannery or for toughening nets.

Genetic resources

Xylocarpus species are comparatively common and widespread and do not seem endangered, except that mangrove forest have been cut in many regions. In locations where Xylocarpus is cut in favour of other mangrove species, it can become endangered.

Prospects

The cultivation of Xylocarpus granatum in the drier mangrove areas is worth considering. It might be an interesting plant for industrial tannage because the tree recovers easily after the bark has been removed. In addition, it is easy to propagate and has a comparatively high tannin content.

Major references

• Mabberley, D.J., Pannell, C.M. & Sing, A.M., 1995. Meliaceae. In: Foundation Flora Malesiana (Editor). Flora Malesiana, Series 1, Volume 12. Rijksherbarium/Hortus Botanicus, Leiden University, Leiden, Netherlands. pp. 1–407.

• Rudjiman, 1991. Xylocarpus Koenig. In: Lemmens, R.H.M.J. & Wulijarni-Soetjipto, N. (Editors). Plant Resources of South-East Asia No 3. Dye and tannin producing plants. Pudoc, Wageningen, Netherlands. pp. 128–130.

• Styles, B.T. & White, F., 1991. Meliaceae. In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. 68 pp.

• Sukardjo, S., 1998. Xylocarpus J. König. In: Sosef, M.S.M., Hong, L.T. & Prawirohatmodjo, S. (Editors). Plant Resources of South-East Asia No 5(3). Timber trees: Lesser-known timbers. Backhuys Publishers, Leiden, Netherlands. pp. 591–594.

• Tomlinson, P.B., 1986. The botany of mangroves. Cambridge University Press, Cambridge, United Kingdom. 413 pp.

• White, F. & Styles, B.T., 1963. Meliaceae. In: Exell, A.W., Fernandes, A. & Wild, H. (Editors). Flora Zambesiaca. Volume 2, part 1. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. pp. 285–319.

Other references

• Allen, J.A., Krauss, K.W. & Hauff, R.D., 2003. Factors limiting intertidal distribution of the mangrove species Xylocarpus granatum. Oecologia 135: 110–121.

• Barbosa, F.M.A., Cuambe, C.C. & Bandeira, S.O., 2001. Status and distribution of mangroves in Mozambique. South African Journal of Botany 67: 393–398.

• Beentje, H.J., 1994. Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi, Kenya. 722 pp.

• CSIR, 1950. The wealth of India. A dictionary of Indian raw materials and industrial products. Raw materials. Volume 2: C. Council of Scientific and Industrial Research, New Delhi, India. 427 pp.

• Decary, R., 1946. Plantes et animaux utiles de Madagascar. Annales du Musée Colonial de Marseille, 54e année, 6e série, 4e volume, 1er et dernier fascicule. 234 pp.

• Hassan, A.S. & Cheek, M., 1999. Meliaceae. In: Thulin, M. (Editor). Flora of Somalia. Volume 2. Angiospermae (Tiliaceae-Apiaceae). Royal Botanic Gardens, Kew, Richmond, United Kingdom. pp. 228–238.

• Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 pp.

• Mainoya, J. R., Mesaki, S. & Banyikwa, F.F., 1986. The distribution and socio-economic aspects of mangrove forests in Tanzania. In: Kunstadter, P., Bird, E.C.F. & Sanga Sabhasri (Editors). Man in the mangroves: the socio-economic situation of human settlements in mangrove forests. Proceedings of a workshop held at Nong Nuch Village, Pattaya, Thailand, 27–31 May 1985. United Nations University, Tokyo, Japan. 117 pp.

• Shinoda, Y., Iwata, S. & Tayima, T., 1987. The chemical composition of mangroves: 3, The bark [in Japanese]. Research Bulletin of the Faculty of Agriculture, Gifu University, Japan 52: 147–158.

• White, F., Styles, B.T. & Gonçalves, A.E., 1979. Meliaceae. In: Mendes, E.J. (Editor). Flora de Moçambique. No 42. Junta de Investigações Científicas do Ultramar, Lisbon, Portugal. 51 pp.

• Zaridah, M.Z., Idid, S.Z., Omar, A.W. & Khozirah, S., 2001. In vitro antifilarial effects of three plant species against adult worms of subperiodic Brugia malayi. Journal of Ethnopharmacology 78(1): 79–84.

Sources of illustration

• Rudjiman, 1991. Xylocarpus Koenig. In: Lemmens, R.H.M.J. & Wulijarni-Soetjipto, N. (Editors). Plant Resources of South-East Asia No 3. Dye and tannin producing plants. Pudoc, Wageningen, Netherlands. pp. 128–130.

Author(s)

• P.C.M. Jansen, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Jansen, P.C.M., 2005. Xylocarpus granatum J.König. In: Jansen, P.C.M. & Cardon, D. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 18 December 2024.

• See the Prota4U database.