Family: Lecythidaceae
Common Name: Fish Poison Tree
Synonym: Agasta asiatica
Habit: Large Tree
Height: 60ft
Origin: Madagascar, Philippines, Polynesia
Uses: This tree contains a poison called Saponin. The plant is pounded, pulped or grated to release the poison which is used to stun fish in freshwater streams.
Garden Location:Ocean Trail, Alakahi Stream Trail

Barringtonia asiatica (Fish Poison Tree, Putat or Sea Poison Tree) is a species of Barringtonia native to mangrove habitats on the tropical coasts and islands of the Indian Ocean and western Pacific Ocean from Zanzibar east to Taiwan, the Philippines, Fiji, New Caledonia, Solomon Islands, the Cook Islands, Wallis and Futuna and French Polynesia. It is grown along streets for decorative and shade purposes in some parts of India, for instance in some towns on southeastern shore. It is also known as Box Fruit due the distinct box-shaped fruit it produces. The local name futuis the source of the name for the Polynesian island Futuna. The type specimen was collected by botanist Pehr Osbeck on a sandy beach area on the island of Java, later to be described (and given the original name of Mammea asiatica) by Carl Linnaeus in his Species Plantarum in 1753.

It is a small to medium-sized tree growing to 7–25 m tall. The leavesare narrow obovate, 20–40 cm in length and 10–20 cm in width. Fruit produced as mentioned earlier, is otherwise aptly known as the Box Fruit, due to distinct square like diagonals jutting out from the cross section of the fruit, given its semi spherical shape form from stem altering to a subpyramidal shape at its base. The fruit measures 9–11 cm in diameter, where a thick spongy fibrous layer covers the 4–5 cm diameter seed.

The fruit is dispersed in the same way as a coconut – by ocean current – and is extremely water-resistant and buoyant. It can survive afloat for up to fifteen years; it was one of the first plants to colonise Anak Krakatau when this island first appeared after theKrakatau eruption.When washed ashore, and soaked by rain water, the seeds germinate.

All parts of the tree are poisonous, the active poisons including saponins. Box fruits are potent enough to be used as a fish poison. The seeds have been used ground to a powder to stun or kill fish for easy capture, suffocating the fish where the flesh is unaffected.

Barringtonia asiatica is a common plant in the Malaysian Mangroves and wetlands such as the Kuching wetlands and Bako National Park. Barringtonia asiatica is known locally as Putat laut or Butun.

Its large pinkish-white, pom pom flowers give off a sickly sweet smell to attract bats and moths which pollinate the flowers at night.