Syzygium setosum (Myrtaceae), a rare and endangered peat swamp tree in Southeast Asia: lectotypification, conservation status and a new record in Sumatra

Abstract

Syzygium setosum (King) I.M. Turner (Myrtaceae), a poorly known peat swamp tree endemic to Peninsular Malaysia, is recorded for the first time in Sumatra, Indonesia. This study was conducted based on morphological characters examined on herbarium specimens of the taxon preserved at various herbaria pertinent to the Southeast Asian flora. The description of S. setosum is amended following the new collections from Peninsular Malaysia and Sumatra. The distribution of this obligate peat swamp species is updated and includes the eastern side of Sumatra and the western side of Peninsular Malaysia. The conservation status of the taxon is assessed. With the available data, the taxon is provisionally assigned here as "Endangered" [EN] with the main threat coming from habitat loss. Field images of the taxon from Sumatra are provided. A lectotype is designated here for Eugenia setosa King.