A tall emergent tree that can reach a height of more than 50 m in the forest. Pagoda shaped crown. Simple leaves arranged in whorls. Fluted trunk. Usually found in lowland forests and swamps. Native.

This is a native species that is critically endangered in the wild in Singapore. Specimens still can be found in the Central Catchment & Bukit Timah Nature Reserves. It is unique from other members of the Alstonia genus in that it has pneumatophores, or breathing roots, hence its scientific name. In swampy areas, these will poke out of the soil above the water surface to allow exchange of gases. This particular specimen at the Singapore Botanic Gardens does not exhibit growth of pneumatophores as the soil is well drained. This Tree is believed to be in excess of 160 years of age, perhaps much older. It is believed that only 15 remaining wild specimens in Singapore exists and there is no record of it being planted in SBG, so it is presumed to be a remnant pre-1859, of native swamp forest that formerly existed in the Gardens. The specimen is exceptionally beautiful with a perfect clean bole and symmetrical canopy. One of the rarest native trees of Singapore that is easily seen by the public. This Tree is evidence of a now very reduced vegetation type.