Magnolia (PROSEA)

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Plant Resources of South-East Asia
Introduction
List of species


Magnolia L.


Protologue: Sp. pl. 1: 535 (1753); Gen. pl., ed. 5: 240 (1754).
Family: Magnoliaceae
Chromosome number: x= 19;M. candollii: 2n= 38

Vernacular names

  • Chempaka (trade name). Magnolia (Am, En, Fr)
  • Thailand: champe
  • Vietnam: dạ hợp.

Origin and geographic distribution

Magnolia comprises about 120 species. About one third of these are found from south-eastern North America to southern Brazil. The remainder occur in tropical South-East Asia from India and the Himalayas to Indo-China, China, Japan, Taiwan, Thailand and throughout the Malesian region. Within Malesia 17 species are found.

Uses

The wood of Magnolia is used for general construction under cover, bridge building, interior finish, panelling, partitioning, flooring, door and window frames, furniture, mouldings, sporting goods, musical instruments, handicrafts, canoe building and pencil slats. It is also applied for the production of veneer, sometimes fancy veneer (e.g. M. elegans ), and plywood.

Several species of Magnolia have been introduced into Malesia and are cultivated for their showy and fragrant flowers. In southern Sumatra the bitter leaves of M. macklottii, rubbed with salt, have been taken against fever. The fragrant flowers are sometimes worn in the hair or used to perfume clothing.

Production and international trade

Magnolia timber is generally traded together with that of other Magnoliaceae genera as "chempaka", although that of Elmerrillia is sometimes traded separately, e.g. in Papua New Guinea. Supplies are very limited and in 1992 only about 900 m3of chempaka timber with a value of about US$ 87 000 was exported from Sabah.

Properties

Magnolia yields a lightweight to medium-weight hardwood with a density of 390-825 kg/m3at 15% moisture content. Heartwood white to pale brown with narrow, grey-brown layers of marginal parenchyma, occasionally with green tinge in M. elegans , not or only moderately clearly differentiated from the white to pale yellow sapwood; grain straight; texture moderately fine and even; wood slightly greasy and sometimes rough to the touch. Growth rings distinct, boundaries indicated by marginal parenchyma; vessels moderately small to medium-sized, solitary and in radial multiples of 2-4, open, tyloses infrequent, occasional white deposits; parenchyma sparse, apotracheal in marginal bands, producing distinctive markings on back-sawn surfaces; rays very fine to moderately fine; ripple marks absent.

The wood air seasons moderately fast. It is soft (e.g. M. elegans ) to moderately hard (e.g. M. candollii ) and relatively strong. When exposed to the weather or in contact with the ground, the wood of harder and heavier M. candollii is reported as non-durable, but that of other species (e.g. M. elegans ) is moderately durable. It is very easy to work but material of M. candollii dulls tools readily due to some hard, chalky deposits in the vessels.

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

Botany

  • Shrubs or small to large trees up to 60 m tall; bole columnar to slightly crooked in small trees, up to 80(-115) cm in diameter, sometimes with small buttresses; bark surface smooth becoming scaly or fissured, sometimes hoop-marked, inner bark yellowish to fawn, often aromatic.
  • Leaves arranged spirally, simple, entire; stipules large, adnate to or free from the petiole.
  • Flowers terminal, solitary, enclosed in 2 bracts when young; tepals 9-21, in 3-5 whorls, white, creamy or greenish, occasionally the outer whorl forming a calyx; stamens many, arranged spirally, anthers usually with an elongated connective; gynoecium sessile or shortly stipitate, with few to many, usually free carpels which are arranged spirally, ovules 2(-5) in each carpel.
  • Fruiting carpels free, woody, dehiscing along the dorsal suture.
  • Seed with sarcotesta, often hanging from its funicle.
  • Seedling with epigeal germination; cotyledons emergent, leafy; hypocotyl elongated; all leaves arranged spirally.

Growth is sympodial. A single 45-year-old M. elegans tree in the arboretum of the Forest Research Institute Malaysia, Kepong measured 28 m in height and 64 cm in diameter. The flowers are protogynous, i.e. the stigmas are receptive before the pollen is shed, and are pollinated by beetles which feed on the stigmas, pollen, nectar and secretion of the petals.

The genera Aromadendron, Talauma and several non-Malesian genera have all been united with Magnolia. M. candollii is highly variable and 5 varieties have been recognized.

Ecology

Magnolia occurs scattered in lowland or montane, primary rain forest, up to 2800 m altitude. The habitat is usually well-drained but occasionally waterlogged and swampy.

Silviculture

Magnolia can be propagated by seed. Seeds of M. elegans with the sarcostesta still attached show about 20% germination in 24-86 days, those of M. candollii about 45% in 24-34 days.

Genetic resources and breeding

The risk of genetic erosion of timber-yielding Magnolia species is determined by the extent of deforestation of their habitat.

Prospects

It is unlikely that the use of Magnolia wood will increase in the near future.

Literature

53, 101, 163, 198, 238, 260, 267, 341, 436, 464, 540, 829, 831, 832, 850, 851, 861, 933, 934, 1038, 1039, 1221, 1239, 1242.