Putat laut, Barringtonia asiatica (Lecythidaceae) is a tree of sandy seashores where its trunk often leans over the beach. It can grow to 30 m tall and 1 m diameter but more usually is 7–20 m tall. Its bunches of large, obovate leaves at the tips of the stout twigs are striking in their glossiness and size. They are large, 15–52 x 7–21 cm, and rather rubbery in texture. In contrast, the petioles are short, barely 0.5 cm long. Its inflorescences are erect, up to 20 cm long and produce 3–20 flowers. Among all the putat species in Malaysia, it has the largest flowers and fruits.
The flowers have white petals measuring 5.5–8 x 2.5–4.5 cm, but it is the many, 15 cm-long stamens that are most striking. They are white and joined into a ring at the base but above are free, pink, red or purple and look like a giant powder puff. Among the stamens is a sturdy style terminating in a knob-like stigma. The ovary is inferior. These flowers are nocturnal, the petals and stamens unfold at sunset and are fragrant. The flower lasts only one night and by the next morning the ring of stamens has fallen to the ground. Only one or two flowers open each night. The combination of fragrance, night-flowering and the large, powderpuff -like flower suggest that they are pollinated by bats.
Their fruits are exceptionally large and are strongly tetragonous-quadrangular at the base and taper to the two persistent sepals at the tip. They are 8.5–11 cm long and measure 8.5–10 cm wide across the base. The outer fruit layer is thick and spongy and the fruits float and are dispersed by sea currents. They are often found in the flotsam washed ashore by sea currents. Its seeds are oblong and 4–5 cm long.
Like most seashore trees, it is widespread ranging from Madagascar to India and Sri Lanka, throughout SE Asia to Australia and the Pacific and Caribbean islands. In Malaysia, its distribution is limited to areas with a sandy coastline. In Peninsular Malaysia it is recorded from islands off the Kedah mainland, to sandy coasts in Penang, Perak, Terengganu, Pahang and Johor (Prain, 2012) and in Sabah from the Sandakan area and in Sarawak from the Kuching district (Pinard, 2002). On sandy seashore it forms what ecologists call the ‘Barringtonia formation’ together with a characteristic assemblage of species such as penaga laut, Calophyllum inophyllum L. (Guttiferae) and rhu, Casuarina equisetifolia L. (Casuarinaceae).
In Borneo, Pinard (2002) reported that its fruits are pulped and thrown into streams as a fish poison and that the bark, leaves and fruits are ‘used in the treatments of backache and sore joints’. No uses have been recorded from Peninsular Malaysia, although on sandy shores it plays an ecological role in protecting the coast from erosion.
