The breathing roots are large, conical with pointed tips.
The flowers have hard sepals that are green on the outside and pinkish on the inside. The flowers bloom at night. The petals are small and white. What is seen as a big pom-pom are a bunch of many many stamens (that produce pollen). These usually drop off the morning after the bloom, and the mud may be littered with hundreds of these tiny white stamens.
Fruits rounded, with the sepals forming a star-shape behind them.
More about the role of Perepat in durians
Links to more on Perepat
from the Guide to the Mangroves of Singapore
Perepat (Sonneratia alba)
These are rare
Berembang (Sonneratia caseolaris)
Gedabu (Sonneratia ovata)