Barringtonia macrostachya grows as a shrub or tree up to 30 metres (100 ft) tall, with a trunk diameter of up to 95 centimetres (37 in). The bark is brown, greenish yellow, greyish brown or brown mottled grey. The fruits are obovoid, up to 9 cm (4 in) long. The specific epithet macrostachya is from the Greek meaning "large spike", referring to the inflorescence. Habitat is riverine and swamp forest, from sea level to 1,300 metres (4,300 ft) altitude. Local medicinal uses include the treatment of ringworm, sore eyes and stomach aches. B. macrostachya has been used as fish poison. It is found in China, Burma, Thailand, Vietnam, Malaysia, Brunei, Indonesia and the Philippines.