Ganophyllum (PROSEA)
Introduction |
Ganophyllum Blume
- Protologue: Mus. Bot. Lugd.-Bat. 1: 230 (1850).
- Family: Sapindaceae
- Chromosome number: x= unknown; 2n= unknown
Vernacular names
- Mangir (trade name). Scaly ash (En)
- Indonesia: kayu mangir (Indonesian), ki angir (Sundanese), tapus (Sumatra)
- Malaysia: panapok ayer (Dusun, Sabah)
- Philippines: arangen (general), lulibas (Tagalog), salngen (Iloko).
Origin and geographic distribution
Ganophyllum comprises 2 species, one in West and Central Africa, the other, G. falcatum Blume (synonym: Dictyoneura integerrima Radlk.), is found from the Nicobar and Andaman Islands, throughout the Malesian region towards the Solomon Islands and northern Australia.
Uses
The strong and fairly durable wood of Ganophyllum is used for house and bridge construction, scantlings, lining, light framing, panelling, flooring, door and window frames, furniture, cabinet work, moulding, boat building (decking, planking), poles for transmission lines, fresh and salt-water piling, railway sleepers, mine timber, vehicle bodies, striking tool handles, sporting goods (e.g. badminton rackets), pestles, archery bows, brush ware, clog soles, toys, match splints and matchboxes, pattern making and turnery. It is suitable for the manufacture of plywood, face veneer, and pulp and paper. It has been used for fuel.
The wood and the bark contain saponin and have been used to make soap, against head lice and as a fish poison. The sawdust has been proven to be an appropriate medium for oyster mushroom (Pleurotus ostreatus Fries) cultivation. The seed yields a solid fat used for illumination and to make a hard soap.
Production and international trade
G. falcatum is generally traded in mixed consignments of medium-weight hardwood. Small amounts are occasionally imported in such consignments into Japan from Papua New Guinea and the Solomon Islands. In 1996 Papua New Guinea exported 2785 m3 of "scaly ash" logs at an average free-on-board (FOB) price of US$ 100/m3.
Properties
G. falcatum yields a medium-weight to heavy hardwood with a density of 650-1000 kg/m3 at 15% moisture content. Heartwood pale yellow-brown to pale brown, not clearly differentiated from the pale yellow-white to pale brown, 1.3-3.0 cm wide sapwood; grain usually straight, occasionally slightly interlocked; texture moderately fine and even; sometimes with slight flame figure on back-sawn face; fresh wood occasionally with unpleasant smell. Growth rings indistinct to very distinct; vessels very small to medium-sized, solitary and in radial multiples of 2-3, barely visible to the naked eye, chalky white deposits present; parenchyma paratracheal vasicentric tending to aliform and confluent, apotracheal in marginal or in seemingly marginal bands, or diffuse; rays extremely fine to very fine; ripple marks absent to irregular.
Shrinkage of the wood is high, it seasons well, but checks negligibly when back-sawn. It takes about 8 weeks to air dry boards 25 mm thick from green to air dry, and 5-8 days to kiln dry them. The wood is moderately hard, strong and tough. It is usually fairly easy to saw and machine, but some trees are considerably harder than others. The peeling properties are good and the bond strength of both steamed and unsteamed veneer using casein glue meets standard requirements. The wood is durable under cover, but non-durable when exposed to the weather or in contact with the ground. The sapwood is permeable, the heartwood is extremely resistant to preservative treatment. The wood is resistant to dry-wood termites when under cover; the sapwood is non-susceptible to Lyctus. Sawdust and exudate from the wood may cause irritation to the eyes and throat whereas splinters may cause skin infection.
The energy value of the wood is 17 785 kJ/kg. Wood extractives have been proved to possess termiticidal activity.
See also the tables on microscopic wood anatomy and wood properties.
Botany
- A possibly monoecious, medium-sized to large tree up to 43 m tall; bole usually straight and cylindrical, sometimes poorly shaped with flutes or bosses, branchless for up to 30 m, up to 150 cm in diameter, sometimes with small, thick buttresses; bark surface scaly, red-brown to dark grey-brown or dark purple-brown, paler where it peels off in papery scales, inner bark pinkish to pale yellow or yellowish-brown; slash with some watery exudate; crown spreading. Twigs, leaves and inflorescence with glandular scales.
- Leaves arranged spirally, paripinnate, (4-)5-8(-10)-jugate, exstipulate; leaflets alternate or rarely opposite, entire, distinctly oblique at base.
- Flowers in an axillary inflorescence, solitary or in cymules on racemoid branches, unisexual, male and female ones in different inflorescences; sepals (4-)5(-7), almost free to connate up to half of their length; petals absent; disk annular, short-haired. Male flower with 5(-7) stamens; pistillode well-developed. Female flower with a superior, 2(-3)-locular ovary with 2 ovules in each cell, style short, columnar.
- Fruit a 1-2-seeded drupe.
- Seed without arillode.
- Seedling with epigeal germination; cotyledons emergent; hypocotyl elongated; first 2 leaves opposite or subopposite, paripinnate, petiole and rachis channelled, subsequent leaves alternate, leaflets crenate, not or only slightly oblique at base.
Early growth is rapid with an average height of 8.2 m and an average diameter of 6.0 cm at the age of 2.5 years. When planted in a mixed plantation with Tristaniopsis at 1500 m altitude, growth was slower with an average height of 19 m and an average diameter of 22 cm at the age of 22 years. The main flowering period is from August to November. Flowers are pollinated by insects, probably bees. Fruits occur in November-March, and are eaten and dispersed by birds.
In the Philippines the name Ganophyllum obliquum (Blanco) Merr. has sometimes been applied erroneously to G. falcatum . The name actually refers to a species of Dysoxylum (Meliaceae).
Ecology
G. falcatum is scattered in primary and secondary, evergreen to monsoon rain forest, sometimes in savanna vegetation or along forest edges, up to 700(-1200) m altitude. It is generally found in well-drained locations on clay, sand, or rocky soils overlying limestone but is also found on river banks, along the inner edge of mangrove forest and on floodplains. In Java it may be quite common in teak forest.
Silviculture
G. falcatum can be raised from seed. The fruit pulp should be removed by maceration and the seeds dried. Fresh seeds have a germination rate of about 80% in 2-4 weeks. When stored under ambient conditions, viability drops fairly rapidly and seeds stored for 10 weeks have only 20% germination. Seedlings are not resistant to oxygen deficiency of the soil and die after 8 days. In a trial in West Java containerized planting stock of G. falcatum planted at 3 m × 1 m grew satisfactorily on only moderately fertile soil. It tolerated a fairly large amount of shade, but only a few stems were well-formed and most had over-heavy branches. The canopy closed at the age of 2.5 years. On the basis of this trial it was recommended to use a spacing of 2 m × 1 m. For the production of sawn timber the estimated rotation is 100 years with an estimated annual production of 0.9 m3/ha of sawn timber, 0.7 m3/ha of wood for poles and 1.6 m3/ha of fuelwood. G. falcatum is not fire-resistant.
Genetic resources and breeding
There are no records of present-day ex situ conservation of G. falcatum. As it is quite common and relatively widespread there seems to be no risk of genetic erosion.
Prospects
G. falcatum may have potential for increased use from natural sources. Its potential as a plantation crop deserves increased attention.
Literature
40, 70, 119, 124, 125, 161, 163, 260, 300, 302, 304, 340, 341, 346, 348, 405, 436, 464, 488, 533, 536, 595, 780, 861, 868, 908, 933, 934, 947, 1048, 1074, 1083, 1132, 1199, 1221, 1261.
U.A. Dasuki