Arytera (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Arytera Blume

Protologue: Rumphia 3: 169 (1847).

Family: Sapindaceae

Chromosome number: x= unknown; 2n= unknown

Vernacular names

• Indonesia: kayu sampi (Bali), ki lalayu (Sundanese), penjalinan (Javanese)
• Malaysia: bedara emping, kelayu hitam, tampong kechil (Peninsular)
• Philippines: alasan (Filipino)
• Thailand: seefan, taet ling (peninsular).

Origin and geographic distribution

Arytera comprises about 28 species and is distributed from north-eastern India and Burma (Myanmar) to southern China, Indo-China, Thailand, the entire Malesian region, the Solomon Islands towards northern and eastern Australia and the Pacific east to Tonga and Samoa. Centres of diversity are located in New Guinea and New Caledonia. Only one of the 12 species found within Malesia yields timber: A. litoralis Blume (synonyms: A. geminata Lauterb. & K. Schumann, A. gigantosperma Radlk., A. xerocarpa (Blume) Adelb.). This species is widespread and occurs from north-eastern India to Indo-China, southern China, Thailand, across Malesia east to the Solomon Islands.

Uses

The wood of A. litoralis is used for rafters in local house construction and for fencing. In India it is also used for agricultural implements and tool handles.

The fruits are rather sour but edible. The conical crown and abundant colourful fruits make A. litoralis a potential ornamental tree.

Production and international trade

There are no records of commercial trade of Arytera timber. It is probably only used on a local scale.

Properties

Arytera yields a medium-weight to heavy hardwood with a density of 700-1120 kg/m³at 15% moisture content. Heartwood pinkish or pale red, not clearly differentiated from the sapwood; grain usually straight; texture very fine to fine and even. Growth rings distinct to indistinct, boundaries marked by narrow, marginal parenchyma; vessels moderately small, solitary and in radial multiples of 2-3(-more), open or blocked by white chalky deposits; parenchyma sparse, paratracheal vasicentric, and apotracheal in marginal or seemingly marginal bands; rays extremely fine; ripple marks absent.

The wood is hard, strong and tough. It is non-durable when exposed or in contact with the ground. The sapwood is susceptible to Lyctus .

See also the table on microscopic wood anatomy.

Botany

A monoecious, small to medium-sized tree up to 40 m tall, rarely a shrub; bole often twisted, usually branching rather low, up to 90 cm in diameter, with plank-like buttresses up to 1.6 m high; bark surface smooth or scaly, greyish-green to dark reddish or almost black. Leaves arranged spirally, paripinnate, 1-6-jugate, exstipulate; leaflets opposite or subopposite, petioluled, entire, usually with domatia in the axils of main veins. Flowers in an axillary to pseudoterminal or rarely ramiflorous panicle, functionally unisexual, usually 5-merous; calyx dentate; petals about as long as the calyx, with 2 scales at base inside; disk entire; stamens (6-)8(-10); ovary superior, 2-3-locular with 1 ovule in each cell, puberulous, style 1. Fruit a coriaceous capsule, with 1-2(-3) well-developed lobes. Seed dull brown to blackish, with an apically open yellowish arillode. Seedling with hypogeal germination; cotyledons not emergent; hypocotyl not elongated; epicotyl with a few small scales; all leaves arranged spirally, first pair of leaves with 2 leaflets, leaflets conduplicate.

A. litoralis flowers and fruits throughout the year and is probably duo-dichogamous, which means that an initial male phase is followed by a female phase which is then followed by a male phase again. The flowers are pollinated by insects, probably bees. The seeds are eaten and dispersed by birds which are attracted by the striking contrast between seed-coat and arillode.

Ecology

A. litoralis is scattered but may be locally common in brackish habitats. It is found in primary and secondary forest on a wide variety of soil types, up to 1500 m altitude.

Silviculture A. litoralis may be propagated from seed. Seeds sown with adhering aril have 90-95% germination in 18-58(-101) days.

Genetic resources and breeding

There are no records of ex situ conservation of A. litoralis . Due to its wide area of distribution it does not seem to be threatened.

Prospects

Because of its poor shape it is unlikely that A. litoralis will gain importance as a timber. It may prove a useful ornamental tree.

Literature

70, 163, 340, 341, 371, 436, 595, 825, 829, 831, 934, 1038, 1048, 1108, 1221.

J.L.C.H. van Valkenburg