5147

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

Crypteronia Blume

Bijdr. fl. Ned. Ind.: 1151 (1826).

CRYPTERONIACEAE

x = unknown; 2n = unknown

Malaysia: bekoi (Peninsular), rambai-rambai (Sabah). Philippines: tiaui (general). Burma (Myanmar): anambo yon (Tenasserim). Cambodia: trap toum. Laos: 'sa am. Thailand: ka-am (north-eastern), ka som (peninsular), khap (northern). Vietnam: loi.

Crypteronia comprises 7 species and is distributed from India (Assam and Bengal) to Burma (Myanmar), Indo-China, Thailand and throughout the Malesian region.

The wood of Crypteronia is used for general construction and house building, furniture, often for flooring or interior finish. It is sometimes applied as a substitute for meranti (Shorea spp.). It may be useful as a fuelwood.
In Malaysia some species are planted for ornamental purposes. In Java young shoots have been eaten raw as a flavouring with rice.

Supplies are generally too limited for commercial trade in Crypteronia timber. Consumption is most probably only local.

Crypteronia yields a medium-weight hardwood with a density of 500-805 kg/m³ at 15% moisture content. Heartwood reddish or greyish-brown, or pale brown with a pinkish tinge, not clearly demarcated from the pale red sapwood; grain straight or slightly wavy; texture rather fine and even; taste astringent. Growth rings generally just discernible with a hand lens by the absence of the apotracheal parenchyma or presence of marginal parenchyma; vessels moderately small to medium-sized, solitary and in radial multiples of 2-3, open or filled with a yellow-white chalky substance; parenchyma moderately abundant, apotracheal diffuse and diffuse-in-aggregates, visible with a hand lens, and scanty paratracheal, indistinct; rays fine or moderately fine, visible with a hand lens; ripple marks absent.
The wood seasons well. It is moderately hard, tough and moderately strong and is easy to work. It is moderately durable under cover.
See also the table on microscopic wood anatomy.

Evergreen, medium-sized to large trees up to 45 m tall; bole columnar, up to 100 cm in diameter, often fluted at base, sometimes with steep buttresses; bark surface rugose to fissured, sometimes finely so, flaking in small pieces, brown or reddish-brown to grey, inner bark granular to fibrous, red to brown. Twigs with thickened nodes and longitudinal lines. Leaves opposite, simple, entire, with minute or rudimentary stipules. Inflorescence consisting of racemes aggregated in a large to poorly branched panicle. Flowers small, bisexual or unisexual and then trees dioecious (C. paniculata), 4-5(-6)-merous; receptacle puberulous; petals absent; stamens usually 5; ovary superior, 2-4-locular with many ovules; style 1. Fruit a small capsule with all floral parts persistent, splitting loculicidal. Seed with a narrow membranous wing.
Young leaves are deep blue. In the Malesian region trees appear to be flowering and fruiting almost throughout the year, but especially at the beginning of the dry season. In Indo-China the flowering season is reported to be in November-December and the fruiting season in January-February. The seeds are dispersed by wind. C. griffithii is inhabited by non-aggressive ants of the genus Cladomyrma.
When still in the vegetative stage Crypteronia species are sometimes mistaken for those of Syzygium or Memecylon. They can, however, be distinguished from Syzygium by the lines present on the twigs and the scarcity of intramarginal veins, and from Memecylon by the usually thicker bark. Two varieties of C. paniculata are distinguished: var. affinis (Planch.) Beus.-Osinga with puberulous leaves and young twigs and var. paniculata with glabrous ones.

Crypteronia species are quite rare and found scattered in primary rain forest or monsoon forest under perhumid to subhumid conditions (the Lesser Sunda Islands), from the lowland up to 1300(-1800) m altitude. They are reported from both clayey and sandy soils and from river banks, slopes, ridges, ravines and forest margins.

Althought detailed information is lacking, the rare and scattered occurrence of Crypteronia species render them vulnerable to genetic erosion or extinction by habitat destruction.

Due to the limited supplies it is unlikely that the utilization of the wood will increase in the near future.

[70]Backer, C.A. & Bakhuizen van den Brink Jr., R.C., 1963-1968. Flora of Java. 3 volumes. Wolters-Noordhoff, Groningen.
[93]Bärner, J., 1942-1961. Die Nutzhölzer der Welt [Timbers of the world]. 4 volumes. J. Neumann, Neudamm.
[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.
[198]Cockburn, P.F., 1976-1980. Trees of Sabah. 2 volumes. Sabah Forest Records No 10. Forest Department Sabah, Sandakan.
[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.
[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.).
[464]Ilic, J., 1990. The CSIRO macro key for hardwood identification. CSIRO, Highett. 125 pp.
[543]Keng, H., 1990. The concise flora of Singapore. Gymnosperms and dicotyledons. Singapore University Press, Singapore. 222 pp.
[632]Kraemer, J.H., 1951. Trees of the western Pacific region. Tri-State Offset Company, Cincinnatti. 436 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.
[933]Research Institute of Wood Industry, 1988. Identification, properties and uses of some Southeast Asian woods. Chinese Academy of Forestry, Wan Shou Shan, Beijing & International Tropical Timber Organization, Yokohama. 201 pp.
[934]Reyes, L.J., 1938. Philippine woods. Technical Bulletin No 7. Commonwealth of the Philippines, Department of Agriculture and Commerce. Bureau of Printing, Manila. 536 pp. + 88 plates.
[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.
[1117]van Beusekom-Osinga, R.J. & van Beusekom, C.F., 1975. Delimitation and subdivision of the Crypteroniaceae (Myrtales). Blumea 22: 255-266.
[1148]van Vliet, G.J.C.M., 1975. Wood anatomy of the Crypteroniaceae sensu lato. Journal of Microscopy 104: 65-82.
[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.

E. Boer (general part), M.S.M. Sosef (general part, selection of species)

Crypteronia borneensis
Crypteronia cumingii
Crypteronia elegans
Crypteronia griffithii
Crypteronia macrophylla
Crypteronia paniculata

Boer, E. & Sosef, M.S.M., 1998. Crypteronia Blume. 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:
Crypteronia borneensis
Crypteronia cumingii
Crypteronia elegans
Crypteronia griffithii
Crypteronia macrophylla
Crypteronia paniculata