Nauclea orientalis is a species of tree in the Rubiaceae family.

 

It is commonly known as the Leichhardt tree and yellow cheesewood, among other names. It grows to a maximum of around 30 m (98 ft) in height and has large glossy leaves.

 

It bears spherical clusters of fragrant flowers that develop into golf ball-sized edible but bitter fruits. The yellowish to orange soft wood is also used for timber and in woodcarving and folk medicine. It is native to Southeast Asia, New Guinea, and Australia.

 

The tree is cultivated for ornamental purposes. The fruits of the tree are edible and are eaten by Indigenous Australians, though it is very bitter-tasting. They are also eaten by flying foxes and birds (like Cassowaries).

 

In Malaysia, it is one of the food sources of proboscis monkeys (Nasalis larvatus), along with other members of Rubiaceae.

 

The wood is easily cut (hence the common name of "cheesewood") but is not durable to weather exposure. It is distinctively yellowish to orange in color. The timber is used for frames and internal floorboards. It is also used in woodcarving, paper production, house construction, and for making canoes.

 

The bark is also used to make fish poison. The extract is added to slow-moving bodies of water to stun fish and make them easier to catch.

 

In folk medicine, bark infusions cause vomiting and are used by Indigenous Australians to treat stomachaches and animal bites. It is the source of a yellow dye. In the Philippines, it is used to treat wounds.

 

Studies on indole alkaloids extracted from Leichhardt trees have also pointed to possible antimalarial and anticancer effects.