Systematic studies of Bornean Zingiberaceae IV. Alpinioideae of Lambir Hills, Sarawak

This paper completes an account of the subfamily Alpinioideae (Zingiberaceae) of Lambir Hills National Park, Sarawak, Malaysia, started in the first paper of this series (Sakai & Nagamasu, 1998), which lists 12 Amomum species from the park. Twenty-two species in the genera Alpinia, Elettaria, Elettariopsis, Etlingera, Hornstedtia and Plagiostachys (Zingiberaceae) are reported from Lambir Hills, Sarawak, with systematic and ecological notes. Four species, Etlingera baramensis, E. inundata, E. newmanii and Plagiostachys glandulosa, are described as new to science, and Hornstedtia leonurus is reported from Borneo for the first time. In Etlingera inundata floral dimorphism is reported. The informal grouping of Etlingera proposed by Smith (1986b) is re-examined. Synonymies of Etlingera coccinea, Hornstedtia minor, H. affinis and H. phaeochoana and the generic position and synonymies of H. sarawacensis and H. conica are discussed. Lectotypes of Achasma brevilabrum (=Etlingera brevilabrum), Alpinia ligulata, Elettaria coccinea (=Etlingera coccinea), Elettaria speciosa (=Etlingera elatior) and Hornstedtia alliacea (=H. conica) are designated. Keys are also provided to all Bornean genera and species of Alpinioideae.