pronounced: ter-oh-KAR-puss IN-dick-uss
Pterocarpus is derived from the Greek πτερον (pteron), a wing, and καρπος (karpos), fruit, referring to the flat, winged pods characteristic of the genus; indicus is Latin, of India.
The tree is a native to south-east and east Asia, and to the northern and south-west Pacific region, and is now widely distributed throughout the tropics. The tree pictured has been planted on the Horseshoe Bay foreshore. There is another near the Early Childhood Centre in Nelly Bay, and one in the Enterprise car park near the ferry terminal in Townsville. There are several others in the Perfumed Garden in the Townsville city centre. When grown in the open, it can reach 25 – 35 m tall, with a broad canopy. It is well adapted to strong winds, and usually stands up well to cyclones. It is a very promising multipurpose tree species for the Pacific Islands, being suitable for reforestation, village wood-lots, living fencing, and as an amenity tree. It is in decline, endangered or extinct in much of its natural habitat due to excessive felling for timber.
The imparipinnate leaves are alternate, and the trees are either briefly fully deciduous, or evergreen in uniformly humid areas. The new flush of leaves is light green, turning a dark mid-green. Each leaf has 5 – 11 alternate ovate entire leaflets, each one about 6 – 12 cm by 3 – 7 cm, The terminal leaflet is the largest, with the lowest pair smallest. Flowering often begins before the new leaf flush, and continues through the leaf flush. It takes place in several short bursts, each lasting one or two days. The flowers, borne profusely in branched axillary racemes, are pea-shaped, bright yellow to orange yellow, about 1.5 cm long, and fragrant. The thin, papery winged indehiscent seed pods, borne in clusters, are disk-shaped, 5 or 6 cm in diameter, light green, turning dull brown when fully mature. Each pod is divided internally into 4 or 5 seed chambers, but only one or two usually contain developed seeds. Some of the pods fall, but many remain on the tree for some months. The bean-shaped seeds are flattened, 6 – 8 mm long, with a brittle leathery seed coat. Dispersal is mainly by wind, but the pods can float and be dispersed in this way by riverine populations. Where the soil under the tree is moist, as in the Townsville Perfumed Garden, the fallen seeds germinate very readily, and the resulting saplings can be a nuisance.
The flowers are visited by many bee species, including honeybees, and beekeepers find it an important source of nectar and pollen.
This tree produces rosewood, one of the world’s most highly prized cabinet timbers, called rosewood because it is rose-scented. It is highly decorative, easily cut and worked by saws, planes and other tools. It turns well, makes excellent veneer, and is highly sought after for craft work and furniture making. The heartwood is streaked, light yellowish brown to reddish brown. In Melanesia it is an important wood for canoes, paddles and outriggers, due to its durability in sea water, and its resistance to marine borers.
In Malaysia, resin from the tree is applied to mouth sores, and root juice to syphilis sores. In Java, young leaves are applied to boils, prickly heat and ulcers. There are many other medicinal uses, including the use of infusions of the wood, which are fluorescent, and herbal teas and pills made from various parts of the tree have in recent years become popular in the treatment of a wide range of diseases and ailments, including leprosy, menstrual pain, flu, rheumatoid arthritis and diabetes.