The nipa palm's trunk grows beneath the ground and only the leaves and flower stalk grow upwards above the surface. Thus, it is an unusual palm tree, and the leaves can extend up to 9 m (30 ft) in height. The flowers are a globular inflorescence of female flowers at the tip with catkin-like red or yellow male flowers on the lower branches. The flower produces woody nuts arranged in a globular cluster up to 25 cm (10 in) across on a single stalk. The ripe nuts separate from the ball and are floated away on the tide, occasionally germinating while still water-borne.