Parinari (PROSEA)
Introduction |
Parinari Aubl.
- Protologue: Hist. pl. Guiane 1: 514, t. 204-206 (1775).
- Family: Chrysobalanaceae
- Chromosome number: x= unknown; 2n= unknown
Vernacular names
- Merbatu (trade name). Parinari, sea beam (En). Brunei: baritu
- Indonesia: kolaka (general)
- Malaysia: bangkawang (Sabah), nyalin, obah ngilas (Sarawak)
- Philippines: baritadiang (general). Burma (Myanmar): tauk-kade
- Thailand: maphok.
Origin and geographic distribution
Parinari comprises 39 species: 18 in the Neotropics, 6 in tropical Africa and 15 in tropical Asia from Indo-China and Thailand, throughout the Malesian region (13 species) towards northern Australia, Fiji and Samoa.
Uses
The wood of Parinari is used for medium and heavy construction under cover, posts, beams, parquet flooring, panelling and packaging for heavy articles. When treated it can be used for wharf decking, transmission posts and railway sleepers, dunnage, salt-water piling and other marine constructions. It provides a good fuelwood and excellent charcoal.
The fruits of several species are edible but apparently little used. The oil obtained from the seeds is used as lacquer and to coat paper umbrellas.
Production and international trade
Parinari wood is probably traded in mixed consignments of medium-heavy hardwood, or together with that of the genera Atuna and Maranthes as "merbatu". Supplies are generally limited, but fairly large amounts of P. papuana are exported from the Solomon Islands to Japan: 6.1% of the total log export from the Solomon Islands to Japan in 1987.
Properties
Parinari yields a medium-weight to heavy hardwood with a density of 630-1010 kg/m3at 15% moisture content. Heartwood red-brown, sometimes with a yellow tinge and not clearly demarcated from the paler sapwood, sapwood up to 7 cm wide in P. papuana ; grain straight to slightly interlocked; texture moderately coarse but even; wood sometimes slightly streaked, that of P. papuana slightly oily to the touch. Growth rings indistinct, occasionally visible as darker coloured bands of fibres with fewer vessels and less parenchyma; vessels medium-sized to very large, exclusively solitary, often in oblique arrangement, tyloses very rare; parenchyma moderately abundant (e.g. P. oblongifolia ) to abundant (e.g. P. costata ), apotracheal in narrow, more or less continuous bands, visible to the naked eye; rays very fine, only visible with a hand lens; ripple marks absent.
Shrinkage upon seasoning is moderate to high. Boards of P. costata 13 mm and 38 mm thick take respectively 1.5 and 3.5 months to air dry without serious degrade, but with some end-checking and risk of stain. It takes about 3 days to kiln dry 25 mm thick boards of P. papuana from green to 12% moisture content, and surface and end-checking are unavoidable. The wood is very abrasive and difficult to saw and work with hand and machine tools, has a rapidly blunting effect due to silica inclusions, and tends to pick up in planing. It splits easily, which is an advantage for its use for firewood. The wood is only moderately durable when exposed to the weather or in contact with the ground and it is easily attacked by termites. It is easy to treat: P. oblongifolia absorbs about 345 kg/m3of a 50/50 mixture of creosote and diesel oil. The sapwood is occasionally attacked by pinhole borers or termites but is rarely susceptible to Lyctus .
See also the tables on microscopic wood anatomy and wood properties.
Botany
Evergreen, small to large or very large trees up to 50(-60) m tall; bole straight, cylindrical, branchless for up to 25 m, up to 110 cm in diameter, buttresses small and steep or absent; bark surface smooth, characteristically lenticellate, becoming cracked or patchy, with adherent scales, grey to pale brown, inner bark characteristically hard and gritty, pink or orange to red-brown. Leaves arranged spirally, simple, entire, usually hairy below; petiole usually with 2 circular glands above; stipules present, caducous. Inflorescence a much-branched cyme or cymose panicle; bracteoles enclosing small groups of flowers. Flowers bisexual, actinomorphic, with a cup-shaped tomentose receptacle and 5 sepals; petals 5, white; stamens (6-)7-9(-10), inserted unilaterally on the margin of the disk; ovary inferior, inserted on the upper half of the receptacle tube, 2-locular with a single ovule in each cell, style arising from the base of the ovary. Fruit a fleshy drupe with hard endocarp, opening by a pair of basal plugs or stoppers to allow the seedling to escape. Seedling with hypogeal germination; cotyledons not emergent; hypocotyl not developed; epicotyl scaly, all leaves arranged spirally.
In West Java P. sumatrana flowers in June and July. The fruits are known to be dispersed by bats, elephants, primates, squirrels, fruit pigeons, pigs, cassowaries and fish.
The family Chrysobalanaceae is sometimes regarded as a subfamily of the Rosaceae . The Malesian species of Parinari are very uniform in flowers and inflorescences and are mainly identified by means of leaf characteristics. The name Parinarium is an erroneous orthographic variant of Parinari .
Ecology
Most Parinari species occur in primary or occasionally secondary, evergreen, semi-evergreen or more rarely mixed deciduous to dry deciduous forest in the lowlands or on hills and ridges, often along rivers and streams, sometimes ascending into montane areas, up to 1400(-2000) m altitude. They occur scattered but may be locally common and usually prefer well-drained habitats. Few species are found in kerangas and swamp forest.
Silviculture Parinari can be propagated by seed, the stone being the unit of sowing; there are about 165 stones in 1 kg. Stones of P. oblongifolia have about 70%, but germination does not start until 9 months after sowing, and the last seeds germinate after more than 3 years. Trees are shade-tolerant and under natural conditions seedlings establish in small numbers and grow up in primary forest.
Genetic resources and breeding
Apart from trees incidentally cultivated in botanical gardens, there are no records of ex situ conservation of Parinari spp.
Prospects
As Parinari timber is very difficult to saw, its use will probably remain limited to marine constructions and firewood.
Literature
40, 70, 162, 163, 198, 209, 238, 260, 261, 267, 341, 387, 405, 436, 464, 536, 616, 677, 678, 705, 741, 829, 831, 861, 903, 905, 963, 1038, 1048, 1221, 1239, 1242.