|Common Name(s): Rengas, Borneo Rosewood, Tiger Rengas
Scientific Name: Gluta spp. and Melanorrhoea spp.
Distribution: From India to Papua New Guinea
Tree Size: 100-130 ft (30-40 m) tall, 2-4 ft (.6-1.2 m) trunk diameter
Average Dried Weight: 48 lbs/ft3 (765 kg/m3)
Specific Gravity (Basic, 12% MC): .63, .76
Janka Hardness: 1,720 lbf (7,650 N)
Modulus of Rupture: 13,100 lbf/in2 (90.3 MPa)
Elastic Modulus: 1,915,000 lbf/in2 (13.20 GPa)
Crushing Strength: 8,380 lbf/in2 (57.8 MPa)
Shrinkage: Radial: 2.9%, Tangential: 5.3%, Volumetric: 8.2%, T/R Ratio: 1.8
Color/Appearance: Heartwood is a deep red with darker streaks, while the sapwood is a lighter pinkish-brown to almost white. Heartwood will darken in color upon exposure to light and air. Sapwood especially is said to be highly irritating to some individuals. Striped pieces are sometimes called Tiger Rengas.
Grain/Texture: Has a fine to medium texture with typically straight or slightly irregular grain.
Endgrain: Diffuse-porous; large to very large pores in no specific arrangement, very few; solitary and radial multiples of 2-3; tyloses present; narrow rays barely visible without lens, spacing normal to fairly close; parenchyma vasicentric, banded, and marginal. Depending on species, heartwood may be fluorescent and/or have extractives readily leaching out in contact with water.
Rot Resistance: Rated as moderately durable, though not resistant to termites or other insects.
Workability: Severely dulls cutting tools due to a high silica content. Otherwise, wood is fairly easy to work and glues and finishes well.
Odor: May have a distinct odor depending on species.
Allergies/Toxicity: The sap of Rengas is reported to be strongly irritating to the skin, causing blisters, sores, and reactions similar to poison ivy, as well as fever and constitutional effects in some individuals. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.
Pricing/Availability: Occasionally available as turning or craft blanks. Expect prices to be in the mid to upper range for an imported hardwood.
Sustainability: Rengas is not listed in the CITES Appendices, and several species in the Gluta genus are reported by the IUCN as being of least concern; an exception is Gluta papuana, a species endemic to New Guinea, which is reported as vulnerable due to a population reduction of over 20% in the past three generations, caused by a decline in its natural range, and exploitation.
Common Uses: Turned objects, cabinetry, furniture, and other specialty wood items.
Comments: It has been reported that Rengas is an excellent and handsome wood for cabinetry and other projects, but that the tree is so highly irritating among foresters and end-users, that it has fallen out of favor. The sap contains urushiol (the same allergen found in Poison Ivy), and can still be irritating to some sensitized individuals even after the wood has been dried, and sap can also seep through some wood finishes to the surface of the wood.
Sometimes referred to as Borneo Rosewood, it is not closely related to the true rosewoods (Dalbergia genus), but is rather contained in the Anacardiaceae family, (which includes poison ivy).