Chisocheton (PROSEA)

Plant Resources of South-East Asia
Introduction

Protologue: Bijdr. fl. Ned. Ind. 4: 168 (1825).

Family: Meliaceae

Chromosome number: x= unknown;C. cumingianussubsp.balansae(C. DC.) Mabb.:n= 23,C. cumingianussubsp.cumingianus: 2n= 92,C. lasiocarpus: 2n= 46

Vernacular names

Chisocheton (En, trade name)
Malaysia: lantupak (Sabah)
Papua New Guinea: kiso (Pidgin)
Vietnam: quếch.

Origin and geographic distribution

Chisocheton comprises 50 species occurring from India to Indo-China, southern China, Thailand, the Nicobar and Andaman Islands and throughout Malesia to northern Australia, the Solomon Islands and Vanuatu. The highest number of species is found in Borneo (18) and New Guinea (13).

Uses

The wood of Chisocheton is used for light construction, ship and boat building, interior finish, furniture and cabinet work, light flooring, mouldings, lining, wall panelling, brushware, sporting goods, boxes and crates, toys, turnery, rotary veneer and plywood. The wood has also been applied in the manufacture of blockboard and particle board and is suitable for the production of pulp.

The leaflets are used for wrapping sago, fish and other food for cooking. The seeds of some species yield an oil which has been used as an illuminant. In the Philippines the oil used to be used commercially to make soap and as a hair cosmetic. The fruits of some species are edible, but reputedly not tasty.

Production and international trade

Small amounts of Chisocheton timber are imported into Japan from Papua New Guinea. In 1996 about 11 500 m³of Chisocheton logs was exported from Papua New Guinea at an average free-on-board (FOB) price of US$ 101/m³. In 1987 0.3% of the timber exported from the Solomon Islands to Japan comprised Chisocheton timber. Its use in other countries is probably on a local scale only.

Properties

Chisocheton yields a medium-weight hardwood with a density of 425-790 kg/m³, sometimes to over 1000 kg/m³at 12% moisture content. Heartwood usually pale brown to pink-brown, fairly bright yellow in some species, not differentiated from the white to straw-coloured sapwood; grain fairly straight to slightly interlocked; texture moderately fine to moderately coarse, uneven because of abundance of wood parenchyma; prominent watered-silk figure on tangential surface and palisade marking on radial surface; freshly cut wood with strong onion smell. Growth rings indistinct but distinct in C. lasiocarpus , boundaries sometimes indicated by a zone of denser fibres; vessels medium-sized to moderately large, solitary and in radial multiples of 2-4(-5), open or filled with solid white or dark-coloured, gum-like deposits; parenchyma abundant, visible to the naked eye, scanty paratracheal and vasicentric, apotracheal in more or less continuous, wide, wavy bands close together, and sparse diffuse; rays moderately fine, visible with a hand lens; ripple marks absent.

Shrinkage is moderate to high; kiln drying is fairly rapid and satisfactory, though with some tendency to distort, individual boards may collapse appreciably. The wood is moderately hard, moderately strong and moderately tough. It is fairly easy to work and a good finish can be obtained at a cutting angle of 20; nailing, peeling and gluing properties are good and the wood polishes well. The wood is non-durable; sapwood is permeable to impregnation but heartwood is resistant. It is not resistant to blue stain. The sapwood is susceptible to Lyctus .

See also the tables on microscopic wood anatomy and wood properties.

Botany

Dioecious or polygamous, small to medium-sized trees occasionally up to 30(-40) m tall; bole usually straight, branchless for up to 18 m, up to 75(-150) cm in diameter, sometimes fluted, stilt-rooted or with narrow buttresses up to 3 m high; bark surface variable, smooth to finely fissured or cracked or dippled, sometimes lenticellate, sometimes scaly or flaking, blackish-brown to red-brown or greenish-grey, inner bark pale fawn or pinkish to orange-red or dark red-brown, with white or watery exudate, often with strong onion or garlic-like odour. Leaves alternate, pinnate and pseudogemmulate or imparipinnate, exstipulate; leaflets opposite, entire. Inflorescence axillary, sometimes cauliflorous or epiphyllous, paniculate, thyrsoid or racemose on a long peduncle. Flowers usually unisexual; calyx cup-shaped, obscurely or rarely distinctly 3-6-lobed; petals (3-)4-6(-14), in 1 or 2 whorls; stamens united into a cylindrical tube which bears (3-)4-10(-30) anthers; disk usually absent; ovary superior, 2-8-locular with 1 or 2 ovules in each cell, style head club-shaped or discoid. Fruit a 2-5(-8)-valved capsule with leathery to woody pericarp. Seed arillate or with a well-developed sarcotesta. Seedling with hypogeal, semi-cryptocotylar germination; cotyledons succulent, peltate; all leaves spiral, first few leaves scale-like, subsequent ones simple followed by compound ones.

The leaves of most species are pseudogemmulate, i.e. they have an indeterminate growth as a result of an apical bud which produces new leaflets over a period of several years, during which time the older leaflets are lost. The trees usually develop a sympodial crown, but are sometimes unbranched and sometimes pachycaul, i.e. develop a comparatively thick primary stem. The growth form corresponds to Champagnat's architectural tree model, characterized by the indefinite superposition of orthotropic axes, each axis becoming pendulous with a renewal shoot arising from the upper surface, or Corner's architectural tree model, characterized by a single unbranched axis with lateral inflorescences. Pollination is probably by insects. Some species have strongly scented flowers, particularly in the evening, suggesting moth pollination. Fruits are eaten by birds, e.g. hornbills, cassowaries and birds of paradise, who thus disperse the seeds.

C. cumingianus and C. pentandrus are both divided into 3 subspecies. C. lasiocarpus is highly polymorphic with a complex of local forms which were formerly given the status of species.

Ecology

Chisocheton species are fairly common in the understorey of South-East Asian rain forest. The taller timber-producing species belong to the subcanopy and canopy layers. They occur in primary or less often secondary lowland and hill or rarely montane forest, up to 1500(-1800) m altitude. Individual species have been reported from riparian forest, floodplains, dipterocarp forest and from forest on limestone. C. lasiocarpus persists in logged-over forest and in forest subject to grazing. Some species have ants living in the twigs and sometimes also in the inflorescence axis and leaf rachis.

Silviculture Chisocheton can be propagated by seed. In germination tests in Peninsular Malaysia seeds of C. ceramicus had almost 100% germination in 1-2.5 months, C. patens seeds had 65% germination in 2-6 months, but seeds with pulp of C. macrophyllus had only 30% germination in 2-6 months.

Genetic resources and breeding

Most of the timber-producing Chisocheton species are comparatively widespread. As they are usually not specifically sought after there seems no immediate danger of genetic erosion, although some rare species like C. koordersii and C. stellatus could easily become endangered.

Prospects

Silvicultural information on Chisocheton is lacking, but as its wood properties are favourable it holds some potential for the future.

Literature

40, 70, 125, 162, 163, 238, 267, 300, 304, 341, 346, 347, 348, 389, 402, 403, 436, 467, 487, 536, 727, 780, 829, 831, 878, 933, 974, 1038, 1058, 1065, 1221, 1232.