Decaspermum is a genus of flowering plants in the myrtle family, Myrtaceae, placed in the order Myrtales. It was first described by naturalists Johann Reinhold Forster and Georg Forster in their 1775 work Characteres Generum Plantarum. The genus comprises roughly 40 accepted species of shrubs and small trees. Botanical synonyms recorded for the genus include Dodecaspermum, Nelitris, and Pyrenocarpa, reflecting a history of taxonomic revision within Myrtaceae.
Decaspermum is native to a broad swathe of the Asia-Pacific region: continental populations occur in southern and southeastern China (including Hainan and Guangdong) and mainland Southeast Asia, while island populations extend through Malesia (Borneo, the Philippines, Sulawesi, Java, and the Maluku Islands) and New Guinea, into the Bismarck Archipelago, the Solomon Islands, and Micronesia (including the Mariana Islands). In Australia the genus reaches Queensland. Further east, species occur on numerous Pacific island groups, including Fiji, Vanuatu, Samoa, Tonga, Wallis and Futuna, and the Society Islands.
Individual species tend to occupy fairly localized ranges within this broader distribution — several are known only from a single island or archipelago (for example, Fiji for Decaspermum vitiense, or Samoa, Tonga, Wallis & Futuna, and the Society Islands together for Decaspermum fruticosum) — while others, such as Decaspermum parviflorum, span a much wider area from China through Assam and mainland Southeast Asia to Papuasia and Micronesia. This pattern of many narrow-range island endemics alongside a few broadly distributed species is characteristic of woody Myrtaceae genera across the Indo-Pacific.
Distribution
Decaspermum is native to southern and southeastern China, Southeast Asia, Malesia, New Guinea, Queensland (Australia), and numerous Pacific island groups including Fiji, Vanuatu, Samoa, Tonga, and the Society Islands. GBIF distribution records corroborate this broad Asia-Pacific range, with individual species typically confined to narrower sub-regions such as a single island group.
Taxonomy Notes
The genus was first described by Johann Reinhold Forster and Georg Forster in 1775 (Characteres Generum Plantarum) and is accepted within Myrtaceae (order Myrtales). Recorded synonyms are Dodecaspermum J.R.Forst. ex Scop., Nelitris Gaertn., and Pyrenocarpa H.T.Chang & R.H.Miao (the last not validly published). GBIF lists 40 accepted species under the genus.
