Dipterocarpus retusus, commonly known as hollong, is a large tree and perhaps the best known species in the genus Dipterocarpus. It is native to China, Vietnam, Philippines, Laos, Cambodia, Malaysia, Indonesia, Myanmar, and India.[1] The tree, some 20m–30mm (70feet–100feetm) tall, is found in Cambodia in dense forests of the plains, common on hillsides and along rivers and in forests between 800m (2,600feet) and 1500m (4,900feet) altitude.
Hollong is the state tree of Assam and Arunachal Pradesh, India.[2] In India, the timber is used for plywood and making various containers. In China, the timber is used in construction. Hollong is a sacred tree for Moran community of Assam.
It is farmed for its timber and resin. In Cambodia, the resin is collected by people in the mountainous regions, in order to make torches and candles, while the wood is used in construction to make columns and boards.