Anisophyllea (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Anisophyllea R. Br. ex Sabine

Protologue: Trans. Hort. Soc. London 5: 446 (1824).

Family: Anisophylleaceae

Chromosome number: x= unknown; 2n= unknown

Vernacular names

• Leechwood (En)
• Indonesia: kayu ribu
• Malaysia: dalek (general), mertama, sial menahun (Sarawak).

Origin and geographic distribution

Anisophyllea comprises about 30 species which are distributed in southern Asia (from Sri Lanka and India to Malesia), tropical Africa and tropical South America (one species only in the latter region). In Malesia 15 species occur: 8 in Peninsular Malaysia, 2 in Sumatra, 2 in Lingga and 9 in Borneo. Many species have a limited distribution. A. disticha has the largest area of distribution: throughout western Malesia except Java.

Uses

The hard and durable wood of some Anisophyllea species is used for beams in house construction, interior finish, furniture, tool handles, fence posts, household implements and sliced veneers. The wood of A. disticha is used for making walking sticks and shafts of pikes, spears and lances.

An infusion of the leaves of A. disticha is used medicinally against diarrhoea and dysentery. A decoction of the leaves is used for bathing persons suffering from jaundice, whereas the roots and the leaves are an ingredient of medicines used to relieve fatigue.

Production and international trade

Anisophyllea trees are often too small and too scattered to be important for timber production.

Properties

Anisophyllea yields a heavy hardwood with a density of 800-980 kg/m³at 15% moisture content. Heartwood pink-brown to orange-brown or dark brown, not clearly defined from the sapwood; grain straight; texture medium to coarse and uneven due to the presence of wide rays; wood with conspicuous oak-like silver grain on the radial surface. Growth rings indistinct or absent; vessels medium-sized to large, solitary and in occasional radial pairs, with white chalky deposits; parenchyma abundant, apotracheal diffuse-in-aggregates and in wide bands; rays moderately broad, distinct; ripple marks absent.

The shrinkage of the wood during drying is high. It dries moderately slow to moderately rapid without serious defects except for some slight end checking. The wood is fairly easy to work, moderately durable and difficult to treat with preservatives.

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

Botany

Monoecious shrubs or small to occasionally fairly large trees up to 36 m tall; bole up to 80 cm in diameter, often poorly shaped and slightly fluted at base, occasionally with short buttresses; bark surface smooth to slightly cracking or flaky, sometimes finely fissured or dippled or with horizontal rings, greyish-brown to reddish-brown, inner bark granular, yellow or pink to reddish-brown, sapwood often with strong radial rays, yellow to creamy to reddish-brown. Leaves alternate and distichous, simple, often asymmetrical, entire, with 3-5 longitudinal veins, sometimes pinnately veined ( A. griffithii ), in some species with two additional rows of stipule-like leaves; stipules absent. Inflorescence axillary, spike-like to paniculate. Flowers small, unisexual, polygamous or apparently bisexual, usually 4-merous; calyx with triangular lobes; petals entire to deeply divided; stamens twice as many as petals, usually unequal in length; ovary inferior, 3-5-locular with a single ovule in each cell, generally with 4 styles. Fruit a dry and rather hard-shelled drupe (fleshy in A. disticha ), ellipsoid to pyriform, smooth or ridged, indehiscent, with persistent floral parts, usually 1-seeded. Seedling with hypogeal germination; cotyledons apparently absent, storage function passed on to a specialized hypocotyl. The hypocotyl is contained within the seed-coat and does not appear above the ground. This "storage hypocotyl" does not grow during germination, does not become erect and is eventually abscised.

The development is according to Massart's architectural tree model, determined by an orthotropic, monopodial trunk with rhythmic growth consequently producing tiers of plagiotropic branches. In A. corneri flowering is aseasonal.

Anisophyllea seems to be most closely related to Combretocarpus , which differs in the pinnately veined leaves, the 3-merous flowers and winged fruit. These two genera are often considered to represent a separate tribe ( Anisophylleae ) in the Rhizophoraceae , but recent multidisciplinary studies point to the distinction of a separate family ( Anisophylleaceae ).

Ecology

Anisophyllea species occur scattered, never gregariously, in primary lowland or hill dipterocarp forest, sometimes in old secondary forest. In Sarawak they sometimes occur also in kerangas, up to 1000 m altitude, or very rarely higher. Occasionally, they reach the upper canopy of the forest, but are usually understorey or lower canopy trees.

Silviculture Germination rates of 85-95% in 1-9 months after sowing for stones of A. grandis and of 45% in 7 months to 3 years for fruits of A. griffithii have been reported.

Genetic resources and breeding

Many Anisophyllea species are rare and found only in small forest areas, which suggests they may be threatened by destruction of their habitat or excessive harvesting.

Prospects

Very little is known on the silviculture and timber utilization of Anisophyllea , although the durability and attractive silver grain of the wood may be of future interest. Due to the very limited supply and localized distribution, increased utilization of wood originating from the forest is not foreseen.

Literature

61, 163, 209, 267, 341, 378, 402, 678, 718, 825, 831, 933, 1048, 1221, 1239, 1242.