Bois boeuf – formerly known as Gastonia mauritiana - is a tree endemic to the island of Mauritius. A canopy tree reaching a maximum of six meters, bois boeuf is distinguished by its spongy trunk, thick branches and thick and shiny leaflets. Its compound leaves are heterophyllous: juvenile leaflets are thin and slender with a red midrib and netted veins, while adult leaflets are large and light green. The tree bears large clusters of green-white flowers and fruit occur in a brown capsule.
Bois boeuf was once very common in coastal, dry, palm-rich and intermediate forests. Bois Boeuf is also known to be one of the preferred nesting sites of masked boobies on Ile-aux-Aigrettes.
Bois boeuf is listed as Critically Endangered under the IUCN Red List of Threatened Species.
Along with much of the native and endemic forests of Mauritius, the number of Polyscias maraisiana trees has been significantly reduced since the early days of colonisation. Bois boeuf is used in ecological restoration of coastal areas.
Bois boeuf was once grown as an ornamental plant in Europe due to its popularity because of its heteroblastic leaves.