Garuga (PROSEA)
Introduction |
Garuga Roxb.
- Protologue: Pl. Coromandel 3: 5 (1811).
- Family: Burseraceae
- Chromosome number: x= 13;G. gamblei,G. pinnataRoxb.:n= 13
Vernacular names
- Kedondong (trade name). Garuga (En)
- Indonesia: kayu kambing (Sulawesi, Moluccas), ki langit (Sundanese), wiyu (Javanese)
- Papua New Guinea: garuga
- Philippines: bogo (Filipino), burus (Iloko), (g)abilo (Tagalog).
Origin and geographic distribution
Garuga comprises 4 species, three of which are non-Malesian and occur from the Himalayas to Indo-China, southern China and Thailand. The only Malesian species is G. floribunda Decne (synonyms: G. abilo Merr., G. littoralis Merr., G. pacifica Burkill) which is found from the Himalayas to Bangladesh, south-western China, Hainan, throughout Malesia (except for Sumatra and very rare in Borneo (Sabah) and Peninsular Malaysia), the Solomon Islands, northern Australia, Vanuatu, Samoa and Tonga.
Uses
The wood of G. floribunda is used for general construction, bridge building, posts, light duty flooring, furniture and cabinet work, interior trim, mouldings, shelving, skirting, sporting goods, agricultural implements, boxes and crates, carvings, toys and novelties, turnery and as a "hot" firewood. It is also used for the production of veneer and plywood.
G. floribunda is occasionally planted as a shade tree. The leaves are used for fodder. A decoction of the bark has been given after childbirth. A decoction of the leaves has been used to dye mats made from Corypha leaves black. The fruit is edible.
Production and international trade
Garuga timber is generally traded together with that of many other Burseraceae genera as "kedondong", but comprises only a very small proportion of the total amount traded. Garuga timber sometimes enters the market in consignments of "red canarium" ( Canarium spp.). In 1996 Papua New Guinea exported about 1220 m3of "garuga" logs at an average free-on-board (FOB) price of US$ 100/m3.
Properties
G. floribunda yields a medium-weight to heavy hardwood with a density of 500-900 kg/m3at 15% moisture content. Heartwood pale brown, pink-yellow-brown or dark red-brown, often with dark grey streaks or concentric bands, distinct from the up to 8 cm wide, pale yellow or pale yellow-green sapwood which turns greyish-brown upon drying; grain interlocked or sometimes wavy; texture moderately fine and even; wood slightly lustrous and with prominent "ribbon" figure on radial surface due to interlocked grain. Growth rings indistinct; vessels moderately small to very large, solitary and in radial multiples of 2-3, sometimes in clusters of much smaller vessels, tyloses abundant and dark deposits present; parenchyma paratracheal vasicentric, but mostly indistinct or absent; rays moderately fine; ripple marks absent; radial canals containing dark gummy deposits clearly visible in the rays.
Shrinkage of the wood upon seasoning is low; it seasons well with little degrade and only slight end splitting. It is moderately hard and moderately strong. The wood is easy to saw and work with hand and machine tools. It can be planed to a relatively smooth finish but a reduced cutting angle is recommended to prevent grain picking up on the radial surface. The wood is slightly durable to non-durable. The sapwood is permeable to moderately resistant to pressure treatment, the heartwood is highly resistant. The wood is susceptible to dry-wood termites and liable to stain. The sapwood is susceptible to Lyctus .
See also the tables on microscopic wood anatomy and wood properties.
Botany
A deciduous, small to medium-sized or occasionally fairly large tree up to 30(-40) m tall; bole usually straight, cylindrical, branchless for up to 12 m, up to 120(-225) cm in diameter, with buttresses up to 3 m high; bark surface with adhering scales, grey or grey-white, inner bark firmly fibrous, pink, with little clear, resinous exudate. Leaves arranged spirally, crowded at the apex of twigs, imparipinnate; stipules inserted on the petiole, caducous; leaflets 9-21(-31), subsessile, crenate-serrate; stipellae often present, caducous. Flowers in an axillary panicle, bisexual, 5-merous, with a cupular receptacle; sepals free; petals with inflexed tips; stamens 10, inserted on the margin of the receptacle; disk adnate to the receptacle, 10-lobed; ovary superior, 5-locular with 2 ovules in each cell, stigma lobed. Fruit a fleshy, blue drupe with 1-5 1-seeded pyrenes. Seedling with epigeal germination; cotyledons emergent, palmately 3- or 5-lobed; hypocotyl elongated; first 2 leaves opposite and with 3 leaflets, subsequent leaves arranged spirally and with increasing number of leaflets.
Flowers appear before the new leaves. In general, flowering is at the end of the dry season or the beginning of the rainy season. In Java G. floribunda flowers in June-November and fruits in October-April; in Sulawesi it flowers in September and October; in the Philippines it flowers in March-June and fruits in March-October.
G. floribunda has been divided into 2 varieties. Var. gamblei (King ex J.J. Smith) Kalkman (synonym: G. gamblei King ex J.J. Smith) occurs in continental South-East Asia, whereas var. floribunda is found from Peninsular Malaysia (rare) eastward towards Melanesia. In Malesian literature G. floribunda is commonly erroneously referred to as G. pinnata , which is a continental species.
Ecology
G. floribunda occurs in seasonal climates in primary and secondary, often periodically dry or very dry monsoon forest and thickets, and in lower montane rain forest, up to 1200 m altitude. It is also found in coastal forest, teak forest and on limestone hills, and grows on stony, sandy or clayey soils.
Silviculture G. floribunda can be propagated by seed. There are 15 500-23 000 dry seeds/kg. It is not fire-resistant and can tolerate a periodically high groundwater table.
Genetic resources and breeding
There are no records of G. floribunda in seed or germplasm banks. Trees are occasionally cultivated in botanical gardens.
Prospects
Garuga will probably continue to make up part of the kedondong timber trade group.
Literature
40, 70, 125, 150, 151, 161, 163, 198, 260, 300, 304, 340, 341, 348, 405, 436, 464, 511, 536, 651, 740, 772, 780, 861, 906, 934, 974, 1023, 1048, 1181, 1221.
S. Sunarti