Beilschmiedia (PROSEA Timbers)

Plant Resources of South-East Asia Introduction

List of species

Beilschmiedia Nees

Protologue: Wallich, Pl. Asiat. rar. 2: 61, 69 (1831).

Family: Lauraceae

Chromosome number: x= 12 (n= 12 or 2n= 24 for several non-Malesian species)

Trade groups

Medang: lightweight to medium-weight hardwood, e.g. Beilschmiedia dictyoneura Kosterm., B. lucidula (Miq.) Kosterm., B. madang Blume.

Medang is used as the trade name for the timber of most Lauraceae genera, such as Alseodaphne , Cinnamomum , Cryptocarya , Dehaasia , Litsea , Persea and Phoebe.

Vernacular names

• Medang
• Indonesia: huru
• Philippines: bagaoring (Samar-Leyte Bisaya). Burma (Myanmar): kyese
• Laos: chik dong.

Origin and geographic distribution

Beilschmiedia consists of about 200 species and occurs throughout the tropics, and also in the Himalayas, subtropical China and Taiwan. Tropical Africa is the richest in species; tropical America has some 15 species. The genus is represented throughout the Malesian area by about 50 species, most of which have a small area of distribution.

Uses

The timber is used for light construction, flooring, mouldings, interior finish, furniture, picture frames, interior fitting and carving. In general, medang timber is also suitable for veneer and plywood production.

Production and international trade

The timber of Beilschmiedia is not traded separately, but together with that of other Lauraceae genera as medang, and probably constitutes only a minor proportion of the total amount handled.

In 1984, the total export of medang from Peninsular Malaysia to Singapore was 1500 m³with a value of US$ 62 000, and in 1992 the export from Sabah was 52 000 m³(about 10% as sawn timber) with a total value of US$ 4.3 million. In 1992 in Papua New Guinea, the minimum price for saw logs was US$ 43/m³. Japan imports medang mainly from Sabah and Sarawak.

Properties

Beilschmiedia wood is a lightweight to medium-weight hardwood. The heartwood is pale greyish-brown with dark brown streaks, not sharply demarcated from the pale red-brown or pale brown sapwood. The density is (430-)470-680(-815) kg/m³at 15% moisture content. The grain is usually straight, texture moderately fine. The wood has a slight odour when fresh.

No specific tests on the mechanical properties have been performed on the wood of South-East Asian Beilschmiedia species. However, the properties are probably comparable with those of most other Lauraceae wood.

The rates of shrinkage of medang are moderate to high. The wood is generally easy to air dry.

The wood is easy to saw although some silica is sometimes present. Planing is easy and nailing and peeling properties are good. Medang is usually rated as non-durable and susceptible to termite, Lyctus and fungal attack. The timber should be treated with anti-stain chemicals immediately after sawing. The heartwood is difficult to treat with preservatives, but the sapwood is permeable. Maximum BFCA preservative penetration is 6 mm after 23 days using the diffusion process.

Description

Evergreen shrubs or small or medium-sized to fairly large trees up to 35(-40) m tall; bole up to 80(-110) cm in diameter, not buttressed or with small buttresses up to 1.5(-2) m high; bark surface smooth, lenticellate to fissured and dippled, grey, grey-brown to reddish-brown or dark brown, inner bark granular (not fibrous), red or reddish-brown to dark reddish-brown or dark brown, sometimes creamy, often with a strong aromatic smell; sapwood yellow or yellow-brown when freshly cut. Leaves arranged spirally, alternate, or subopposite to opposite, simple and entire, leathery to rigidly leathery, with glandular dots and aromatic when crushed, pinnately veined, often prominently reticulate below; stipules absent. Inflorescence an axillary, lateral or subterminal raceme or panicle, usually short and few-flowered. Flowers bisexual, regular, 3-merous, small, without an involucre; perianth segments 6, united in a short tube below, subequal, deciduous in fruit; fertile stamens 6 or 9, in 3 rows inserted on the perianth tube, those of the outer 2 rows introrse, those of the inner row extrorse and with 2 glands on each filament, anthers 2-celled and opening with a valve from the base to the top, an innermost row of cordate to ovoid, usually short-stalked staminodes present; ovary superior, sessile, 1-celled, with a single, pendulous, anatropous ovule, style short, conical, obtuse, with an inconspicuous stigma decurrent on one side. Fruit a 1-seeded berry, oblong to ovoid, on a naked, sometimes slightly thickened pedicel. Seed without albumen, with a thin testa; cotyledons large, flat, convex and pressed against each other, succulent; embryo minute. Seedling with hypogeal, cryptocotylar germination; all leaves arranged spirally.

Wood anatomy

• Macroscopic characters:

Heartwood pale greyish-brown with dark brown streaks, not sharply demarcated from the pale red-brown or pale brown sapwood. Grain usually straight. Texture moderately fine; wood with low lustre, no distinctive odour or taste. Growth rings faint to distinct; vessels and rays barely visible to the naked eye; parenchyma not distinct without a lens. Ripple marks absent.

• Microscopic characters:

Growth rings indistinct to distinct, marked by marginal parenchyma bands and slight differences in fibre wall thickness. Vessels diffuse, 3-12/mm², solitary and in radial multiples of 2-6, very rarely in small clusters, round to oval or slightly angular, average tangential diameter 100-220μm; perforations simple; intervessel pits non-vestured, alternate, round to polygonal, 7-10μm; vessel-ray and vessel-parenchyma pits large and simple or with greatly reduced borders; helical thickenings, deposits and tyloses absent. Fibres c. 1200μm long, non-septate, thin-walled to moderately thick-walled, with minutely bordered pits confined to the radial walls. Parenchyma abundant, paratracheal parenchyma vasicentric, apotracheal parenchyma in marginal (or irregular zonate) 1-7 cells wide bands, in 2-4-celled strands. Rays 6-8/mm, (1-)2-4(-5) cells wide, (0.1-)0.3-0.5 mm high, heterocellular, composed of procumbent body ray cells and one or two rows of square to upright marginal cells. Crystals absent or sporadic, prismatic, in ray or axial parenchyma cells. Silica bodies present in some of the species. Oil cells present in only some of the species, associated with ray and axial parenchyma cells, and isolated among fibres.

Species studied: B. acutifolia , B. bullata Allen, B. dictyoneura , B. gemmiflora (Blume) Kosterm., B. glauca S.K. Lee & Lau, B. lucidula , B. roxburghiana Nees, B. sphaerocarpa Winkler.

Growth and development

During germination the fruit splits at one pole and the plumule is released from the envelopments by slight elongation of the cotyledonary petioles. No resting stage occurs. The taproot is long and slender with many slender, unbranched lateral roots. The first leaves are sessile, scale-like and are soon shed.

Although evergreen, most of the species flower and develop new reddish leaves periodically. Pollination is by insects; seed dispersal takes place by animals which eat the fleshy fruits.

Other botanical information

Beilschmiedia is one of the Lauraceae genera in South-East Asia whose species are still comparatively unknown and ill-defined. It requires a thorough taxonomic revision. The present state of knowledge results in doubtful identifications, unreliable nomenclature and often absence of information at the species level.

The genus is probably most closely related to Cryptocarya and Dehaasia and is characterized by the absence of a persistent involucre, a deciduous perianth, the 2-celled anthers, the often reticulately veined leaves and the naked fruiting pedicel which may be slightly thickened.

Beilschmiedia is divided into 2 subgenera: subgenus Beilschmiedia with 9 fertile stamens and subgenus Hexarrhena Stapf with 6 fertile stamens.

In New Zealand, the timber of B. tawa (A. Cunn.) Benth. & Hook.f. ex Kirk, which occurs in montane Podocarpus-Nothofagus-Agathis forest, is fairly well-known and traded under the name "tawa". In Taiwan, B. erythrophloia Hayata is a fairly well-known timber used mainly for plywood production. In tropical Africa, the timber of Beilschmiedia spp. is called "kanda".

Ecology

Timber-producing species of Beilschmiedia usually occur in primary lowland rain forest, sometimes ascending into the montane zone up to 1400(-1750) m altitude. They are elements of the subcanopy or canopy layer but never emergent and are generally found on fertile soils, sometimes in swampy locations, rarely on limestone.

Propagation and planting

Beilschmiedia can be propagated by seed. About 45% of the seed of B. madang germinates in 1-3.5 months. Germination of seed of B. roxburghiana is reported to be good and more or less simultaneous.

Yield

In natural forest in Irian Jaya, on average 0.1 trees/ha are found with an estimated timber volume of 0.14 m³.

Genetic resources

There are no records of germplasm collections nor of any specific activities to conserve the genetic resources of Beilschmiedia . In the Malesian region a large number of species are found and most have a small area of distribution. Therefore, the genetic diversity may be reduced through conversion of natural forest into other vegetation types.

Prospects

Although the species of Beilschmiedia are insufficiently known, they will probably continue to make up part of the medang timber traded, most likely in very much the same proportions as at present.

Literature

• All Nippon Checkers Corporation, 1989. Illustrated commercial foreign woods in Japan. Tokyo. p. 72.
• Burgess, P.F., 1966. Timbers of Sabah. Sabah Forest Records No 6. Forest Department, Sabah, Sandakan. pp. 330-340.
• Kochummen, K.M., 1989. Lauraceae. In: Ng, F.S.P. (Editor): Tree flora of Malaya. A manual for foresters. 2nd edition. Vol. 4. Malayan Forest Records No 26. Forest Research Institute Malaysia. Longman Malaysia SDN. Berhad, Petaling Jaya. pp. 117-123.
• Kostermans, A.J.G.H., 1957. Lauraceae. Reinwardtia 4: 229.
• Kostermans, A.J.G.H., 1964. Bibliographia Lauracearum. Ministry of National Research, Indonesia. pp. 113-155.
• Kostermans, A.J.G.H., 1965. New and critical Malesian plants VII. Reinwardtia 7: 19-46.
• Kostermans, A.J.G.H., 1968. Materials for a revision of Lauraceae I. Reinwardtia 7: 291-356.
• Kostermans, A.J.G.H., 1969. Materials for a revision of Lauraceae II. Reinwardtia 7: 451-536.
• Kostermans, A.J.G.H., 1970. Materials for a revision of Lauraceae III. Reinwardtia 8: 21-196.
• Martawijaya, A., Kartasujana, I., Kadir, K. & Prawira, S.A., 1986. Indonesian wood atlas. Vol. 1. Forest Products Research and Development Centre, Bogor. pp. 68-73.