SYNOPSIS OF BEGONIA (BEGONIACEAE) FROM THE NORTHERN ARM OF SULAWESI AND SANGIHE ISLAND, INDONESIA, INCLUDING THREE NEW SPECIES Author Ardi, W. H. Research Center for Biosystematics and Evolution, National Research and Innovation Agency (BRIN), Jalan Raya Jakarta-Bogor Km 46, Cibinong, Kabupaten Bogor, Jawa Barat 16911, Indonesia. E-mail: wisn 005 @ brin. go. id. wisn005@brin.go.id Author Thomas, D. C. Research and Conservation, Singapore Botanic Gardens, National Parks Board, 1 Cluny Road, Singapore 259569. text Edinburgh Journal of Botany 2022 2022-08-18 79 405 1 50 http://dx.doi.org/10.24823/ejb.2022.405 journal article 10.24823/EJB.2022.405 1747-0036 10524193 6. Begonia gambutensis Ardi & D.C.Thomas [§ Petermannia ], Edinburgh J. Bot. 71: 260 (2014). – Type: Indonesia , Cultivated in Bali Botanic Garden from vegetative material collected in the wild ( Sulawesi , Gorontalo, Bone Bolango district , Suwawa Timur subdistrict, Gunung Gambuta , Desa Pinogu , side of river), 3 ix 2013 , Thomas D.C. & Ardi W.H. 13-802 ( holotype BO ; isotypes E, L ) . Distribution . Indonesia : endemic to Sulawesi , Gorontalo Province (central North biogeographical region), Gunung Gambuta (see Figure 2 ). Habitat . Primary rain forest, forest floor at the side of a river, at c. 700 m elevation. Proposed IUCN conservation category . Data Deficient (DD). This species is known from only a single locality, in the Bogani Nani Wartabone National Park. The forests in the wider area are very poorly collected. Consequently, we assess this species as Data Deficient ( IUCN Standards and Petitions Subcommittee, 2019 ). Additional specimens examined . INDONESIA . Sulawesi . Northern arm of Sulawesi . Central North Sulawesi : Gunung Gambuta (cultivated at Bali Botanic Garden from material collected in the wild), 4 iv 2009 , D.C. Thomas & W.H. Ardi 09-53 ( BO , E ) ; Dumoga Bone National Park , Gorontalo , 14 viii 1991 , W. Milliken 364 ( K ) ; Dumoga Bone National Park , Bolaang Mongondow , 30 ix 1991 , W. Milliken 1137 ( E , K ) . Begonia gambutensis is a very distinct species. It can be easily differentiated from other Sulawesi species by the dense crimson hairs on vegetative parts, male inflorescences showing basal dichasial branching with well-developed internodes and distal monochasial branching, and female flowers with obovate tepals distinctly tapering towards the base ( Ardi et al. , 2014 ).