These are tall trees! They grow to 50-60 m, i.e., about the height of a 15-20 story building. The word bole, of Germanic origin, is quasi-synonymous with trunk, of Latin origin. The straight, cylindrical bole can measure up to 1.50 m (5 ft) in diameter. It is free of branches for two thirds of the tree’s height. What a sight!
They inhabit evergreen and semi-evergreen forests of Southeast Asia, from India, Sri-Lanka, Bangladesh to Cambodia, Laos, Thailand, Myanmar and Vietnam, at elevations between 300 and 1,100 m (1,000-3,500 ft), most usually below 700 m (2,500 ft). If left alone, they can live for about a century.
Leaves are commensurate in size with the height of the tree. The leaf blade is ovate-oblong, 20-30 cm long (up to a foot!), 8-13 cm wide (3-5 in), leathery, smooth or sparsely velvety. Another attractive feature is the flower, 3 to 3.5 cm long, white or pinkish. Sepals are 2 linear, 3 shorter. Flowers can be seen from January to March, while fruiting occurs in May and June. The fruit is another beauty : the seed is borne aloft by the two propeller-like blades attached to it. The name of the genus, Dipterocarpus, is a reference in Latin to that feature.
Yet another quality is the scent of the resin, known as gurjun, used in perfumery : the soft fragrance is woody, sweet, dry, balsamic and resinous. Their sheer size has brought about the downfall of these trees. Even though the wood is not outstanding, it is plentiful. Across Southeast Asia, the trees are turned into plywood by the lumber industry, to such an extent that the species now faces extinction. Too attractive, too visible for its own good!