Aphanamixis (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Aphanamixis Blume

Protologue: Bijdr. fl. Ned. Ind. 4: 165 (1825).

Family: Meliaceae

Chromosome number: x= unknown;A. polystachya: 2n= 36, 76, c. 150

Vernacular names

• Indonesia: kayu gula (general), kedoya sapi (Javanese), komalo (Tobaro, Moluccas)
• Malaysia: chikeh, kulim burong, pasak lingga merak (Peninsular)
• Philippines: salakin (general), gugoloi (Zambales), kunatan (Tagalog)
• Laos: kong ta 'sua, ta pou, ta 'sua
• Thailand: lao hang, ma hang kan (northern), ta suea (central)
• Vietnam: gội, gội gác, gội nước.

Origin and geographic distribution

Aphanamixis comprises 3 species occurring from Sri Lanka, India and Bhutan to Burma (Myanmar), Indo-China, southern China, the Andaman Islands, Thailand and throughout the Malesian region towards the Solomon Islands. The only species yielding timber is A. polystachya (Wallich) R.N. Parker (synonyms: Amoora aphanamixis Schult. & Schult. f., Aphanamixis cumingiana (C. DC.) Harms, Aphanamixis grandifolia Blume, Aphanamixis rohituka (Roxb.) Pierre). It is represented throughout the range of the genus and is occasionally cultivated elsewhere, e.g. in South America and, under glass, in Europe.

Uses

The timber of A. polystachya is used in house construction and for interior fittings, and is suitable for furniture, boat ribs, canoes, vehicle bodies, turnery and veneer and plywood manufacture.

In India the tree has been planted as an ornamental and occasionally to provide shade. The seeds are bruised and boiled to extract an oil used for making soap, as an illuminant and as medicine. The bark has medicinal properties and is used against rheumatism, cold and pain in the chest. In the Moluccas mashed leaves are used in a solution for disease control in rice and extracts from twigs, bark, fruits and seed have an antifeedant effect on a range of insects. All parts of the fruits are poisonous.

Production and international trade

The wood of A. polystachya is used on a local scale only. The seed oil is used solely in areas where the tree grows abundantly.

Properties

A. polystachya yields a medium-weight hardwood with a density of 530-750 kg/m³at 15% moisture content. Heartwood pale to dark red, turning dark red-brown upon exposure, sharply demarcated from the pale pink sapwood, up to 6 cm wide; grain usually interlocked; texture moderately fine to coarse, and uneven; tangential surface with prominent watered-silk figure, radial surface with palisade markings; wood with faint, cedar-like odour when fresh. Growth rings not distinct, marked by closely spaced marginal parenchyma; vessels small to moderately large, solitary and in radial groups of 2-4, open or filled with dark gum-like or chalky white deposits; parenchyma abundant, visible to the naked eye, apotracheal in mostly narrow to sometimes wider wavy bands; rays very fine to moderately fine, visible with a hand lens; ripple marks absent.

The wood seasons well. It is moderately hard, strong and moderately tough. It is somewhat difficult to saw and plane due to the interlocked grain, but takes a good finish. The wood is very durable for interior work and resistant to fungi; the heartwood is resistant to dry-wood termites and the sapwood is non-susceptible to Lyctus .

The seed contains about 43.5% oil.

See also the table on microscopic wood anatomy.

Botany

Sometimes dioecious, small to medium-sized trees up to 20(-35) m tall; bole cylindrical, sometimes crooked, branchless for up to 15 m, up to 70 cm in diameter, sometimes with buttresses up to 1(-2) m high; bark surface cracking to flaking, greyish-brown to reddish-brown, inner bark pinkish to red, often exuding white latex. Indumentum of simple, bifid and stellate hairs. Leaves alternate, imparipinnate, exstipulate; leaflets opposite, entire. Flowers bisexual or unisexual (plants then dioecious), in axillary inflorescences; female and bisexual flowers usually in spikes or racemes, male ones in panicles; calyx deeply 5-lobed; petals 3, basally united with the staminal tube which bears 3-8 anthers; disk absent; ovary superior, 3(-4)-locular with (1-)2 ovules in each cell, style stout, with a conical to truncate head. Fruit a 2-3(-4)-valved capsule. Seed arillate. Seedling with cryptocotylar germination; first pair of leaves opposite, simple and toothed, subsequent leaves alternate and imparipinnate.

In Java A. polystachya flowers throughout the year. The flowers are insect-pollinated; in Papua New Guinea sweatbees have been observed visiting the flowers. The fruits are dispersed by birds.

Aphanamixis belongs to the tribe Aglaieae and is closely related to Aglaia . It differs mainly at microscopic level: the wood having banded parenchyma.

Ecology

A. polystachya occurs in primary and secondary rain forest, up to 1400(-1800) m altitude. It is locally common (especially in New Guinea), is often found along rivers or in floodplains, but has also been reported from seasonally flooded forest, kerangas and forest on limestone.

Silviculture For India it is stated that A. polystachya is a shade-tolerant tree and natural regeneration is abundant in shady and moist locations, close to the mother tree.

Genetic resources and breeding

For A. polystachya chromosome numbers reveal the occurrence of tetraploid and octaploid individuals. Since it is cultivated as well as fairly widespread in the wild, with limited usage, A. polystachya does not seem endangered.

Prospects

Because of its attractive colour and moderately fine grain the wood of A. polystachya is probably suitable for fine furniture and cabinet work. The antifeedant extracts from various parts of the tree need further investigation for possible application in disease and pest control.

Literature

70, 162, 163, 267, 341, 436, 438, 557, 729, 772, 780, 861, 878, 882, 933, 934, 1065, 1104, 1169, 1221, 1232.

T. Uji