Local name Belian or Belian simpoh. The wood is known as Ulin. Note that there are two different trees called Belian in Borneo. Potoxylon melangangai is most common on the west coast of Borneo and Eusideroxylon zwageri which is most common on the east coast of Borneo. Both tree species have very hard, very heavy wood and are most common on river floodplains often in single species stands. The seeds of both species are often found on beaches near river mouths and can be told apart as described below.