Two species of Xylocarpus are recognised in Australia’s mangroves across the northern coast from Western Australia, Northern Territory and Queensland. They are distinguished by the presence of pneumatophores and buttresses, the bark, and the size of mature fruit. Flowers and inflorescences are similar.
2 species in Australia
The genus Xylocarpus J.König (1784) belongs to a large tropical family, the Meliaceae Juss. – the mahogany trees. These consist of 50 genera and over 1000 species - recognised by their unisexual flowers with stamens united by expanded filaments to form a staminal tube. The family is known for its high-quality timber species like Australian Red Cedar (Toona australis (F.Muell.) Harms), and fruit trees like Langsat (Lansium domesticum Correa).
Xylocarpus is comprised of three Indo West Pacific species with: two occurring in mangroves, including X. granatum and X. moluccensis; and a third, X. rumphii (Kostel.) Mabb., normally growing above high water on cliffs, rocks and sandy upland areas. The two mangroves often occur in mixed stands within middle to upper tidal limits of middle to upper estuarine reaches. Trunk and bark characters vary depending on species. Furthermore, X. granatum is evergreen while X. moluccensis is notably deciduous with leaves turning red and orange before falling in the dry winter season. Flowers are small and do not differ between taxa. Fruits are large and globate enclosing a number of angular woody seeds. Fruits vary between species in size and number of seeds. Newly separated seed segments may be pieced back together with some difficulty, hence the common name.
Derivation of Genus Name
‘Xylo-carpus’ means woody fruit (in Latin), and refers to the large and distinctly woody fruit and seeds of this genus.
Xylocarpus occurs in coastal localities from East Africa and India to China, through Asia and Indonesia to New Guinea and northern Australia. In Australia, X. granatum and X. moluccensis are both present.