Gomphia (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Gomphia Schreb.

Protologue: Gen. pl., ed. 8: 291 (1789).

Family: Ochnaceae

Chromosome number: x= unknown; 2n= unknown

Vernacular names

• Brunei: chenaga lampong (Iban)
• Indonesia: kayu ndolak (Batak, northern Sumatra), kayu sepat (southern Sumatra), tengkejing kering (Kalimantan)
• Malaysia: kelutan (Iban, Sarawak), magang-magang (Kadazan, Sabah), mata ketam batu (Peninsular)
• Philippines: minsaray (Mindoro), sasahit (Tagalog), simahima (Bikol)
• Cambodia: kongkea chhmôôl (general), ângkië sël (Kompong Thom), chiëm ântông (Koh Kong)
• Laos: huan²kouang, kouang non (Savannakhet)
• Thailand: hang kwang phu (north-eastern), kapito (south-eastern), thong pling (peninsular)
• Vietnam: cây dủa bâp, dục dạc, mai cánh lờm.

Origin and geographic distribution

Gomphia comprises some 30-36 species which, with one exception, are confined to tropical Africa and Madagascar. The only Asiatic species is G. serrata (Gaertn.) Kanis (synonyms: Campylospermum serratum (Gaertn.) Bittrich & M.C.E. Amaral, G. sumatrana Jack, Ouratea angustifolia (Vahl) Baillon & Lanessan) which occurs from Sri Lanka and India to Indo-China, southern China (Hainan), Thailand, Peninsular Malaysia, Singapore, Sumatra, Borneo, the Philippines and Sulawesi.

Uses

The wood of G. serrata is used in house building (rafters, poles, planks) and has been used for boats, pumps and blocks.

In Peninsular Malaysia the leaves are chewed by native people. In India a decoction of the bitter roots and leaves is applied medicinally as a stomachic and anti-emetic tonic. In Cambodia young branches are used against toothache.

Production and international trade

The wood of G. serrata is used on a local scale only.

Properties

G. serrata yields a medium-weight hardwood with a density of 830-870 kg/m³at 15% moisture content. Heartwood dull red-brown or purple-grey-brown, not clearly differentiated from the sapwood; grain straight to shallowly interlocked; texture fine and uneven; wood with some silver grain. Growth rings indistinct; vessels very small to moderately small, solitary and in occasional radial or diagonal pairs, open; parenchyma moderately abundant, apotracheal diffuse to diffuse-in-aggregates, sometimes appearing as scanty paratracheal, indistinct even with a hand lens; rays of 2 distinct widths, extremely fine and medium-sized; ripple marks absent.

The wood is prone to splitting during drying. It is hard, strong and moderately durable.

See also the table on microscopic wood anatomy.

Botany

A small or medium-sized tree up to 25 m tall; bole up to 40 cm in diameter, slightly fluted at base; bark surface smooth or flaking into thin pieces, dark grey-brown, inner bark fibrous, pink. Leaves arranged spirally, simple, finely toothed, with 2-3 intramarginal veins; stipules united, early caducous. Flowers in an axillary or terminal panicle, 5-merous; sepals enlarged and persistent in fruit; petals yellow or cream; stamens 10, anthers opening by apical pores; gynophore columnar, ribbed; carpels 5, free but sharing a single style, each with a single ovule. Fruit with 1-2(-5) kidney-shaped drupelets, yellowish-green turning dark purple or blue-black when ripe.

In Borneo flowering and fruiting specimens have been collected throughout the year. Seed dispersal is probably effected by birds.

Gomphia belongs to the subfamily Ochnoideae . G. serrata shows considerable morphological variation, probably because of its wide ecological amplitude. It might be that the correct name for G. serrata is actually Campylospermum serratum which is related to the current issues concerning the correct typification of Gomphia and the distinction of Campylospermum from Ouratea .

Ecology

G. serrata is found in primary and secondary, evergreen to semi-deciduous, lowland to submontane rain forest, up to 1500 m altitude, on well-drained infertile soils. It is confined to areas with an everwet to moderately dry monsoon climate, where it is found in a wide range of forest types including kerangas, mixed dipterocarp forest, limestone forest and peat-swamp forest.

Silviculture Attempts to propagate G. serrata by seed failed because of insect damage to the embryos in fresh fruitlets and to the few seedlings that germinated.

Genetic resources and breeding

As G. serrata is not commercially exploited and has a wide ecological amplitude there is no risk of genetic erosion.

Prospects

G. serrata is difficult to propagate from seed and it is unlikely that its timber will be increasingly used in the near future.

Literature

115, 198, 267, 341, 343, 436, 522, 523, 829, 831, 861, 1038, 1039, 1048, 1221.

K.M. Kochummen