E. fusca is a deciduous tree with spiny bark and light orange flowers. Its legume pods reach 20 centimetres (7.9 in) in length and contain dark brown seeds. The seeds are buoyant, allowing them disperse across oceans. The tree is highly adapted to coastal conditions, tolerant of both flooding and salinity.
Like many other species in the genus Erythrina, E. fusca contains toxic alkaloids which have been utilized for medicinal value but are poisonous in larger amounts. The most common alkaloid is erythraline, which is named for the genus. The new buds and leaves are eaten as a vegetable. The easy-to-grow and attractive flowering tree is cultivated as an ornamental shade and hedge plant. It is a common shade tree in cacao plantations. It attracts hummingbirds, which pollinate its flowers.
E. fusca is the official flower of the Venezuelan state of Trujillo.