4999

5(3): Timber trees; Lesser-known timbers

Bouea Meisn.

Pl. vasc. gen.: tab. diagn. 75, comm. 55 (1837).

ANACARDIACEAE

x = unknown; 2n = unknown

Plum mango (En). Malaysia: kundang (general), merapoh (Peninsular).

Bouea comprises 3 species and is found in Burma (Myanmar), the Andaman Islands, Indo-China, southern China, Thailand, Peninsular Malaysia, Sumatra, Java and Borneo. One species is a rare endemic of Vietnam, the other two are more widespread and cultivated within their natural area of distribution, B. macrophylla also in Ambon.

The dark brown centre of the heartwood of Bouea is sought after in Peninsular Malaysia for cabinet work and tobacco pipes. The wood has also been used in house building (e.g. joists, rafters), for scabbards, tool handles and rice pounders. In Indo-China the frequently occurring burrs on the bole are used for joinery.
The dense crowns render Bouea an attractive ornamental shade tree. Fruits are eaten raw, steamed or made into an excellent compote and young fruits are sometimes pickled or made into preserve. The young leaves of B. macrophylla can be eaten raw, e.g. with rice.

Utilization of the wood of Bouea is very limited and on a local scale only.

Bouea yields a medium-weight hardwood with a density of 675-895 kg/m³ at 15% moisture content, but a density of 910-1130 kg/m³ was recorded for two specimens of B. oppositifolia from Indonesia, which implies that it is a heavy hardwood. Heartwood pale brown with a pinkish tinge, reportedly with a core of dark brown wood with black streaks in B. macrophylla, sapwood pale brown with a red tinge, grey-brown or yellowish-brown usually not clearly differentiated from heartwood; it has been stated that the sapwood is up to 7 cm wide; grain straight or interlocked; texture rather coarse but even; wood with attractive zig-zag figure due to darker parenchyma. Growth rings occasionally distinct macroscopically due to wider spacing of banded parenchyma; vessels medium-sized to moderately large, mainly solitary but also in radial multiples of 2-3, tyloses rare; parenchyma moderately abundant, paratracheal vasicentric to occasionally aliform and apotracheal in wide regularly to irregularly spaced bands, the apotracheal parenchyma visible to the naked eye; rays very fine to moderately fine, visible with a hand lens; ripple marks absent.
Wood samples generally season well without defects. The wood is hard and strong. The heartwood is reputed to be durable, but the sapwood is susceptible to Lyctus.
See also the table on microscopic wood anatomy.

Medium-sized to fairly large trees up to 36 m tall; bole up to 80 cm in diameter, not buttressed; bark surface smooth to cracked or finely fissured, dark grey to reddish-brown or pale greyish-brown, inner bark finely fibrous, red or reddish-brown, with gummy exudate; crown very dense. Young twigs often 4-angular; buds pointed and prominent. Leaves decussate, simple, entire, with a resinous smell when crushed. Flowers male or bisexual, small, in an axillary or rarely terminal panicle, 3-5-merous, whitish or pale yellow to yellowish-green; calyx lobed; petals keeled; disk present; ovary superior, 1-locular with 1 ovule, style short, stigma round and flat, sometimes 2-3-grooved. Fruit a drupe. Seed with testa adherent to the endocarp. Seedling with semi-hypogeal germination; cotyledons not or only slightly emergent, fleshy; hypocotyl not elongated; leaves conduplicate.
Growth of B. oppositifolia in Burma (Myanmar) is slow. B. macrophylla is evergreen, B. oppositifolia is deciduous. The inflorescences appear together with the new leaves. In Indonesia B. macrophylla flowers from June-November and fruits from March-June. The fruits of B. macrophylla are dispersed by bats.
Bouea is the only genus within the family Anacardiaceae having decussate leaves. It may be mistaken for genera of other families like Garcinia, Syzygium, Olea or Memecylon, but can be distinguished by the resinous smell of the broken twigs or crushed leaves and the pointed buds.

B. macrophylla occurs naturally in evergreen lowland rain forest up to 300 m altitude; when cultivated it is found up to about 850 m. It thrives on light, fertile soils. B. oppositifolia is found in evergreen to deciduous lowland rain forest including sandy coastal forest and peat-swamp forest, up to 700 m altitude.

Bouea can be grown from seed, but B. macrophylla is also propagated by marcotting or grafting. Seeds rapidly lose their viability and should be sown immediately after collecting. Fruits germinate more slowly and more erratically than stones, which always show 100% germination. Stones of B. macrophylla took 11-22 days to germinate and B. oppositifolia stones took 19-33(-57) days. B. macrophylla needs shade for several months after planting.

B. macrophylla includes several fruit varieties that differ in sweetness. A germplasm collection of B. oppositifolia is maintained in Thailand.

The use of Bouea may increase because it may serve as a multipurpose tree providing timber, fruit and shade.

[162]Burgess, P.F., 1966. Timbers of Sabah. Sabah Forest Records No 6. Forest Department, Sabah, Sandakan. xviii + 501 pp.
[163]Burkill, I.H., 1966. A dictionary of the economic products of the Malay Peninsula. 2nd edition. Ministry of Agriculture and Co-operatives, Kuala Lumpur. Vol. 1 (A-H) pp. 1-1240. Vol. 2 (I-Z) pp. 1241-2444.
[209]Corner, E.J.H., 1988. Wayside trees of Malaya. 3rd edition. 2 volumes. The Malayan Nature Society, Kuala Lumpur. 774 pp.
[267]Desch, H.E., 1941-1954. Manual of Malayan timbers. Malayan Forest Records No 15. 2 volumes. Malaya Publishing House Ltd., Singapore. 762 pp.
[341]Flora Malesiana (various editors), 1950-. Kluwer Academic Publishers, Dordrecht, Boston, London.
[343]Flore du Cambodge, du Laos et du Viêtnam (various editors), 1960-. Muséum National d'Histoire Naturelle, Paris.
[371]Ghosh, S.S., Ramesh Rao, K. & Purkayastha, S.K., 1963. Indian woods: their identification, properties and uses. Vol. 2: Linaceae to Moringaceae. Manager of Publications, Delhi. 386 pp.
[436]Heyne, K., 1927. De nuttige planten van Nederlands-Indië [The useful plants of the Dutch East Indies]. 2nd edition, 3 volumes. Departement van Landbouw, Nijverheid en Handel in Nederlandsch-Indië. 1953 pp. (3rd edition, 1950. van Hoeve, 's-Gravenhage/Bandung. 1660 pp.).
[825]Ng, F.S.P., 1978. Strategies of establishment in Malayan forest trees. In: Tomlinson, P.B. & Zimmermann, M.H. (Editors): Tropical trees as living systems. The proceedings of the fourth Cabot symposium held at Harvard Forest, Petersham, Massachusetts on April 26-30, 1976. Cambridge University Press, Cambridge, London, New York, Melbourne. pp. 129-162.
[829]Ng, F.S.P., 1991-1992. Manual of forest fruits, seeds and seedlings. 2 volumes. Malayan Forest Record No 34. Forest Research Institute Malaysia, Kepong. 997 pp.
[831]Ng, F.S.P. & Mat Asri Ngah Sanah, 1991. Germination and seedling records. Research Pamphlet No 108. Forest Research Institute Malaysia, Kepong. 191 pp.
[861]Oey Djoen Seng, 1951. De soortelijke gewichten van Indonesische houtsoorten en hun betekenis voor de praktijk [Specific gravity of Indonesian woods and its significance for practical use]. Rapport No 46. Bosbouwproefstation, Bogor. 183 pp.
[1038]Smitinand, T., 1980. Thai plant names. Royal Forest Department, Bangkok. 379 pp.
[1048]Soepadmo, E., Wong, K.M. & Saw, L.G. (Editors), 1995-. Tree flora of Sabah and Sarawak. Sabah Forestry Department, Forest Research Institute Malaysia and Sarawak Forestry Department, Kepong.
[1123]van der Pijl, L., 1957. The dispersal of plants by bats (chiropterochory). Acta Botanica Neerlandica 6: 291-315.
[1164]Verheij, E.W.M. & Coronel, R.E. (Editors), 1991. Plant resources of South-East Asia No 2. Edible fruits and nuts. Pudoc, Wageningen. 446 pp.
[1221]Whitmore, T.C. & Ng, F.S.P. (Editors), 1972-1989. Tree flora of Malaya. A manual for foresters. 4 volumes. Malayan Forest Records No 26. Longman Malaysia Sdn. Berhad, Kuala Lumpur & Petaling Jaya.
[1242]Wong, T.M., 1982. A dictionary of Malaysian timbers. Malayan Forest Records No 30. Forest Research Institute Malaysia, Kepong. 259 pp.

D. Sulistiarini

Bouea macrophylla
Bouea oppositifolia

Sulistiarini, D., 1998. Bouea Meisn.. In: Sosef, M.S.M., Hong, L.T. and Prawirohatmodjo, S. (Editors): Plant Resources of South-East Asia No 5(3): Timber trees; Lesser-known timbers. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea

The following species in this genus are important in this commodity group and are treated separatedly in this database:
Bouea macrophylla
Bouea oppositifolia