Alseodaphne (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Alseodaphne Nees

Protologue: Wallich, Pl. asiat. rar. 2: 61, 71 (1831).

Family: Lauraceae

Chromosome number: x= 12;A. keenaniiGamble:n= 12,A. petiolaris(Meissner) Hook. f.:n= 12

Vernacular names

• Medang (trade name)
• Indonesia: huru (Sundanese), malika (Ambon). Burma (Myanmar): kyese-payon.

Origin and geographic distribution

Alseodaphne comprises about 50 species occurring from Sri Lanka, India and Nepal to Indo-China, southern China, Hainan, Thailand, Peninsular Malaysia, Sumatra, Borneo and the Philippines. The Malesian region harbours about 30 species.

Uses

The wood of Alseodaphne is used for house building, interior finish, furniture and cabinet making, carving and agricultural implements. Good-quality veneer and plywood can be manufactured from the wood. Some of the heavier species, like A. bancana may be used for heavy outdoor construction, ship and boat building and salt-water piling.

Production and international trade

The timber of Alseodaphne is generally traded together with that of many other Lauraceae genera as "medang". It constitutes a fair portion of the total amount traded. In 1984 the total export of medang from Peninsular Malaysia to Singapore was 1500 m³with a value of US$ 62 000. Japan imports medang mainly from Sabah and Sarawak. In 1992 exports from Sabah amounted to 52 000 m³(of which about 10% was sawn timber) with a total value of US$ 4.3 million. The timber is locally in great demand. In South Kalimantan timber of A. oblanceolata is available in sufficient and marketable quantities.

Properties

Alseodaphne yields a medium-weight hardwood with a density of 520-855 kg/m³at 15% moisture content. Heartwood pale grey-green to grey-green, moderately sharply differentiated from the pale yellow-green, up to 9 cm wide sapwood, darkening to brown with a green tinge on exposure; grain straight to moderately interlocked; texture moderately fine and even; wood with camphor-like smell when freshly cut; planed surface greasy to the touch. Growth rings indistinct; vessels medium-sized, solitary and in radial groups of 2-4, tyloses often abundant; parenchyma sparse to moderately abundant, paratracheal vasicentric, sometimes confluent in A. penduliflora ; rays very fine to moderately fine, usually only visible with a hand lens; ripple marks absent.

Shrinkage of the wood upon seasoning is low to high. It seasons easily and without serious defects, although there is a slight risk of splitting and surface checking (observed in A. nigrescens ) and very slight risk of cupping or bowing. It takes about 3 months and 4.5-5 months, respectively, to air dry boards 13 mm and 38 mm thick. The wood is fairly strong. It is easy to saw and to plane, with only very slight picking up. Sawdust of the wood near the bark contains small hair-like fibres that irritate the skin. The wood is generally fairly durable under cover, but this is variable for the genus. The average service life of A. insignis wood in graveyard tests in Peninsular Malaysia is 5.7 years; 5-7 years is reported for the wood of other species. The heartwood is resistant to preservative treatment but sapwood is permeable to such treatment. Using a mixture of 50% creosote and 50% fuel oil in various open-tank methods the absorption is 22-46 kg/m³for A. insignis , 8-27 kg/m³for A. nigrescens and over 110 kg/m³for sapwood of these species. The wood is slightly susceptible to borer attacks.

A. perakensis leaves contain alkaloids.

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

Botany

Evergreen or briefly deciduous, small to medium-sized trees up to 30(-40) m tall; bole usually fairly straight, branchless for up to 21 m, up to 60(-100) cm in diameter, sometimes with small or rarely up to 3 m high buttresses; bark surface smooth to fissured or cracking or even scaly, sometimes dippled, often lenticellate, brown, dark brown or grey to yellowish, inner bark yellow to yellowish-brown or orange-brown to red or pink. Leaves arranged spirally, often crowded at the end of branchlets, simple, entire, exstipulate; terminal bud naked or covered with scales. Flowers in a few-flowered, axillary panicle, bisexual; tepals 6, with a short tube, the outer 3 usually smaller than the inner 3, enlarged in fruit and persistent or caducous; fertile stamens 9, in 3 whorls, those of the inner whorl with 2 glands each, anthers 4-celled, opening by valves; ovary superior, 1-locular with a single ovule, stigma peltate. Fruit a black or grey, 1-seeded, ellipsoid berry on an enlarged, fleshy, usually warty pedicel. Seedling with hypogeal germination; cotyledons not emergent, peltate; hypocotyl not developed; epicotyl with a few scales; all leaves arranged spirally.

Growth is in flushes. Some species show distinct sympodial branching resulting in a pagoda-shaped tree. A. bancana is a typical understorey tree in Sepilok, Sabah, with a mean annual diameter increment of less than 0.4 cm. The seeds are dispersed by birds.

Alseodaphne is closely related to the genera Nothaphoebe and Persea , and the three used to be treated as a single genus. Nothaphoebe may be distinguished from Alseodaphne by its many-flowered inflorescences and sessile anthers, whereas both Nothaphoebe and Persea lack the typical enlarged and usually warty fruit stalk. Furthermore, Alseodaphne is also very similar to Dehaasia , the only differentiating character being the number of anther cells. Identification based solely on fruiting material is therefore very difficult. Alseodaphne needs a thorough taxonomic revision, as the status of many species is still doubtful.

Ecology

Most Alseodaphne species occur as understorey trees of non-seasonal, evergreen, lowland to lower montane rain forest, up to 1600 m altitude. They are found in primary and secondary forest on a wide range of soils and may be locally dominant. Several species inhabit lowland swamp forest. A. insignis is found in lowland dipterocarp forest but also in kerangas and peat-swamp forest.

Silviculture Alseodaphne is rather sensitive to fire. Mortality of about 50% has been observed in Indonesia.

Genetic resources and breeding

It is hard to judge whether genetic erosion by destruction of the habitat seriously threatens Alseodaphne , but at least some of the species mentioned below may be vulnerable due to their limited area of distribution.

Prospects

In Peninsular Malaysia Alseodaphne makes up a small, but notable part of the medang timber trade group, but there is no reason to expect an increase in its utilization.

Literature

70, 162, 163, 218, 267, 387, 556, 603, 605, 608, 614, 626, 677, 678, 755, 829, 861, 908, 933, 955, 974, 1040, 1218, 1221, 1242.