Deden Girmansyah

Begonia ranaiensis (Begoniaceae), a new species from Mt Ranai, Natuna Island, Indonesia

SummaryBegonia ranaiensis Girm., a new species from Mount Ranai, Natuna Island, is described and illustrated.

Two new species of Begonia (Begoniaceae) from Borneo

SummaryBegonia mentewangensis and B. dolichobracteata from Borneo, are newly described and illustrated. The habit of B. mentewangensis is similar to B. anthonyi, while the fruit is similar to that of B. guttapila. B. dolichobracteata, with imbricate bracts, is allied to B. imbricata from Sabah. Distribution maps, line drawings and conservation status are provided for each taxon.

Taxonomic status of Begonia promethea (sect. Petermannia, Begoniaceae) in Borneo

The rediscovery of Begonia promethea Ridl. for the first time since its description in 1906 led to the discovery that the later described B. beccarii Warb. is synonymous with it and that it belongs in Begonia sect. Petermannia. It is a rare, endangered species known only from three localities, two locations from the Kuching Division, Sarawak, Malaysia and another one from West Kalimantan, Indonesia. A detailed, illustrated description and a distribution map of Begonia promethea are provided. We suggest an IUCN conservation category of EN B2ab(iii). Lectotypes for both names are designated.

Two new species of Begonia (Begoniaceae) from Long Duhung, Berau Regency, East Kalimantan, Borneo Island, Indonesia

SummaryTwo new species of Begonia (Begoniaceae) from the section Petermannia are described from the Berau Regency, East Borneo: B. ltahensis Girm. and B. duhungensis Girm. The habit of B. ltahensis is similar to B. calcarea, currently known only from the Ltah river in lowland mixed Dipterocarp forest in Long Duhung, Kelay District, Berau Regency. Meanwhile, B. duhungensis is similar to B. heliostrophe from Sabah, found near Long Duhung village. A distribution map, images and conservation status are provided for each taxon.