Baccaurea motleyana commonly known as Rambai is a medium-sized tree of genus Baccaurea Lour and Euphorbiaceae (Spurge family), the same family as related fruits like lang-khae and mafai. The plant is native to Thailand, Peninsular Malaysia, Sumatra, Java, Borneo (Sarawak, Brunei, Sabah, West-, South- and East-Kalimantan) and Moluccas.

Rambai is an evergreen, sub-canopy, dioecious, much branched tree that grows about 8–14 m (26–46 ft.) tall with a trunk of up 40cm in diameter, and a low, round, bushy crown. The plant can be found growing in lowland primary and secondary, tropical rain forest, or open shrub vegetation and rarely riparian forest. The plant grows on alluvial soils, yellow clay, and sand or limestone soils.

The Rambai Bark is said to be very effective and was claimed to cure many types of skin problems such as rashes, ringworm and etcetera.