6018

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

Pajanelia DC.

Bibl. Univ. Genève ser. 2, 17: 130, repr. p. 14 (1838).

BIGNONIACEAE

x = 20; P. longifolia: 2n = 40

Dagger tree (En). Indonesia: abeueng laut (Meulaboh, Aceh), kayu semua (Natuna Islands). Malaysia: beka, bekak gunong, kayu bonglai (Peninsular). Burma (Myanmar): kyaung-dauk, kyaung-sha-letto. Thailand: i-pong, pong (peninsular).

Pajanelia is a monotypic genus occurring from southern India and Sri Lanka through Burma (Myanmar), the Andaman Islands and Thailand towards Peninsular Malaysia, Singapore, northern Sumatra and the Natuna Islands. It was erroneously reported from the Philippines. The single species is P. longifolia (Willd.) K. Schumann (synonyms: P. multijuga (Wallich) DC., P. rheedii Wight).

The wood of P. longifolia has been used in the Andaman Islands for house building, planking and canoes. In the Natuna Island the timber is esteemed for boat building.
In parts of Malaysia it is commonly planted as stakes for hedges along rice fields, and, similar to Oroxylum indicum (L.) Kurz, a hot decoction of the leaves is used externally against stomach disorders. In the Natuna Islands a decoction of the leaves is used against fever.

The wood of P. longifolia is only used locally on a small scale.

P. longifolia yields a lightweight hardwood with a density of 345-375 kg/m³ at 15% moisture content. Heartwood pale grey-brown with a speckled appearance, not clearly demarcated from the sapwood; grain shallowly interlocked; texture rather coarse and even. Growth rings indistinct; vessels medium-sized to moderately large, mostly solitary with occasional radial multiples of 2-3, in tangential arrangement, tyloses occasionally present; parenchyma moderately abundant, paratracheal vasicentric and confluent, occurring as broad sheaths to the vessels, distinct with a hand lens; rays moderately fine, just visible to the naked eye; ripple marks absent.
The wood is soft and non-durable.
See also the table on microscopic wood anatomy.

An evergreen or briefly deciduous, small to medium-sized, glabrous, sparingly branched tree up to 30(-36) m tall; bole up to 115 cm in diameter, without buttresses; bark surface shallowly fissured and lenticellate, grey, inner bark soft, light green. Twigs massive, with large leaf scars; innovations resinous. Leaves opposite, crowded at the end of twigs, exstipulate, pinnate; rachis and petiole sharply keeled above; leaflets opposite or alternate, with a very asymmetrical base and large glands along the midrib below. Flowers in a terminal thyrse up to 1 m long, large, 5-merous, pale yellowish, with a soapy odour; calyx closed in bud, with 5 irregular lobes; corolla zygomorphous, with a broad, dull greenish-red tube, with 5 crisped lobes, pubescent except at base; stamens 4 and a 5^th rudimentary one, inserted about halfway up the corolla tube; disk annular; ovary superior, 2-locular with many ovules, style 1. Fruit a large dagger-shaped capsule with a septum, the valves broadly winged, leathery. Seeds in several rows, hyaline-winged. Seedling with epigeal germination; hypocotyl elongated; first leaves opposite and simple, subsequent ones pinnate.
Saplings are monopodial and unbranched until they reach a height of 4.5-9 m. Growth is rapid, but exact figures are lacking. Flowering has been observed from January to April and in August, fruiting in March to April and in August. Pollination of the nocturnal flowers seems to be by nectarivorous bats, as pollen has been identified in guano samples in Peninsular Malaysia. The seeds seem adapted to wind dispersal but the numerous seedlings observed in coconut stands along the shore suggest they are also dispersed by water.

Pajanelia is found locally common in primary but more often in secondary lowland to montane rain forest, but has also been encountered in monsoon forest, coconut stands near the sea and more open country. It occurs scattered along rivers and along the edges of coastal forest, up to 500(-700) m altitude.

Pajanelia can be propagated by seed, but is rarely planted, e.g. in Aceh, Sumatra.

The fairly wide geographical distribution of P. longifolia and its locally common occurrence indicate that there is no risk of genetic erosion. It is, however, now extinct in Singapore.

The reportedly rapid growth of P. longifolia and its pioneer-like characteristics make it worthwhile to be tested in plantation trials. Although resembling teak to some degree, the wood is much lighter in weight and less durable.

[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.
[527]Kartasujana, I. & Suherdie, 1993. 4000 jenis pohon di Indonesia dan Index 4000 jenis kayu Indonesia (berdasar nama daerah) [4000 Indonesian tree species and an index of 4000 Indonesian timber species (based on their vernacular names)]. Badan Penelitian dan Lengembangan Kehutanan, Jakarta. 135 pp.
[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.
[1038]Smitinand, T., 1980. Thai plant names. Royal Forest Department, Bangkok. 379 pp.
[1039]Smitinand, T. & Larsen, K. (Editors), 1970-. Flora of Thailand. The Forest Herbarium, Royal Forest Department, Bangkok.
[1053]Start, A.N. & Marshall, A.G., 1976. Nectarivorous bats as pollinators of trees in West Malaysia. In: Burley, J. & Styles, B.T. (Editors): Tropical trees. Variation, breeding and conservation. Linnean Society Symposium Series No 2. Academic Press, London. pp. 141-150.
[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.

S.H. Widodo

Widodo, S.H., 1998. Pajanelia DC.. 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