Nauclea orientalis is a species of tree in the family Rubiaceae, native to Southeast Asia, New Guinea, and Australia.

It has many common names, including bur tree, canary wood, Leichhardt pine and yellow cheesewood.

It bears spherical clusters of fragrant flowers that develop into golf-ball-sized edible but bitter fruits.

[3] "Leichhardt pine", however, is more commonly used for the kadam or burrflower tree (Neolamarckia cadamba), a closely related species.

He mistakenly identified it as a closely related Sarcocephalus and remarked on their preponderance near large riverbanks.

[10] Leichhardt trees belong to the genus Nauclea classified under the tribe Naucleeae, subfamily Cinchonoideae of the coffee family (Rubiaceae).

[16] Many authors agree on the view that Linnaeus's description of C. orientalis in 1753 is a mixture of true Nauclea orientalis and a description by Hendrik van Rheede,[17] and the true identity of Rheede's plant (as Katou Tsjaca or Katou Tsjaka[18]) had been variously argued since at least 1798.

[19][20][21] Colin Ernest Ridsdale [es] discussed this matter and supposed that Rheede had intended to describe kadam.

[21] The illustration of the Rheede's plant was later designated as the lectotype of kadam, i.e. Neolamarckia cadamba when Jean Bosser tried to solve the taxonomic problem of that species.

In Nauclea, these interpetiolar stipules are held erect and pressed together, resulting in strongly flattened vegetative buds.

They possess a perianth (each composed of five petals and sepals in separate whorls), The internal surface of the corolla are yellow-to-orange and sweet-smelling.

They are frequently partly fused together, forming a long corolla tube tipped with the individual lobes of the petals.

[6] Their native range extends from tropical Northern Australia and New Guinea to Southeast Asia; from the Philippines to Myanmar and Thailand (the biogeographic region of Malesia).

[30][31] The extract is added to slow-moving bodies of water to stun fish and make them easier to catch.

[3][32] In folk medicine, bark infusions cause vomiting and are used by Indigenous Australians to treat stomachaches and animal bites.

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

[33] Leichhardt trees are susceptible to Lyctus beetles and blue stain fungus (Grosmannia clavigera).