Eucalyptopsis (PROSEA)
Introduction |
Eucalyptopsis C.T. White
- Protologue: Journ. Arn. Arb. 32: 139, t. 1 (1951).
- Family: Myrtaceae
- Chromosome number: x= unknown; 2n= unknown
Vernacular names
- Indonesia: ohong gawa, ohong nikat (Moluccas)
- Papua New Guinea: malaha (trade name).
Origin and geographic distribution
Eucalyptopsis is a genus of only one or perhaps two species. E. papuana C.T. White occurs in the Moluccas and New Guinea.
Uses
The wood of E. papuana is used for general construction, furniture, flooring, joinery, interior trim, panelling, mouldings, turnery and veneer.
Production and international trade
In 1996 Papua New Guinea exported about 2490 m3of "malaha" logs at an average free-on-board (FOB) price of US$ 89/m3.
Properties
E. papuana yields a lightweight to heavy hardwood with a density of 370-970 kg/m3at 12% moisture content. Heartwood pinkish-brown to dark red-brown, sapwood straw to pale pink-brown; grain straight to slightly interlocked; texture moderately fine and even. Growth rings moderately well defined; vessels small to medium-sized, arranged obliquely, solitary and in radial multiples of 2-3(-4), with a few clusters, tyloses abundant; parenchyma predominantly scanty paratracheal, vasicentric to aliform tending to confluent, apotracheal diffuse, sparse; rays not visible to the naked eye; ripple marks absent.
Shrinkage upon drying is moderate; occasionally boards show a slight tendency to develop twist. The wood can be kiln dried from 30% to 12% moisture content in 3-4 days at a dry-bulb temperature of 60-70C; drying rates differ considerably due to large density variations between individual trees. A high-humidity treatment should be given after kiln drying, to relieve stresses. The wood is moderately durable. The heartwood is very difficult to treat with preservatives. The sapwood is sometimes susceptible to Lyctus .
See also the table on microscopic wood anatomy.
Botany
A fairly large to large tree up to 50 m tall; bole straight, up to 70 cm in diameter, with or without buttresses; bark surface somewhat scaly or fissured, brown. Leaves subopposite, simple, lanceolate, entire, petiolate. Flowers sessile, in clusters at the end of the branches of a terminal panicle, white; calyx tube campanulate, with articulation immediately above the ovary and with 4 irregular lobes at apex; petals absent; stamens numerous, attached in 4 groups high up in the calyx tube; ovary inferior or semi-inferior, 2-locular with many ovules, style 1. Fruit a woody capsule, base adnate to the persistent lower part of the calyx tube, apex free and opening with 2 valves. Seed usually 1, oblong, plano-convex.
Eucalyptopsis differs from Eucalyptus by the absence of an intramarginal vein in the leaves, and by the less strictly opposite leaves (subopposite). It is possibly most closely related to Pleurocalyptus from New Caledonia.
Ecology
E. papuana is locally plentiful in the canopy layer of lowland and lower montane rain forest in New Guinea, up to 1500 m altitude.
Genetic resources and breeding
Although it is stated that E. papuana is locally common, so little is known about its distribution and ecology that it is difficult to judge the danger of genetic erosion.
Prospects
Since the wood of E. papuana can be used for many purposes and is of good quality, research on its silviculture is desirable. It might be a timber of future importance.
Literature
216, 297, 300, 302, 304, 348, 861, 1206, 1232.
I. Samsoedin, E. Boer & R.H.M.J. Lemmens