Gardens’ Bulletin Singapore 69(1): 89-95. 2017 
doi: 10.3850/S2010098116000081 
89 
Begonia ignita (sect. Petermannia, Begoniaceae), 
a new species with orange flowers 
from Sulawesi, Indonesia 
C.-W. Lin' D.C. Thomas 2 , W.H. Ardi 3 & C.-I Peng 4 
herbarium of Taiwan Forestry Research Institute, 
No. 53, Nanhai Road, Taipei 100, Taiwan 
2 Herbarium, Singapore Botanic Gardens, National Parks Board, 
1 Cluny Road, Singapore 259569 
3 Bogor Botanic Gardens, Jl. Ir. H. Juanda No. 13, Bogor, Indonesia 
4 Herbarium, Biodiversity Research Center, Academia Sinica, 
Nangang, Taipei 115, Taiwan 
bopeng @ sinica.edu.tw 
ABSTRACT. Begonia ignita C.W.Lin & C.I Peng, a new species of Begonia sect. Petermannia 
from Sulawesi, Indonesia, is here described and illustrated. It is distinct from other species 
in Begonia section Petermannia by a character combination including a procumbent stem 
ascending only at the apex, symmetric or subsymmetric leaves, the presence of a pale band or 
maculation running parallel to the leaf margin, and orange tepals. A detailed comparison with 
a morphologically similar species, the Sulawesi endemic Begonia mendumiae M.Hughes, is 
provided. 
Keywords. Begonia ignita , B. mendumiae, Indonesia, new species, Sulawesi 
Introduction 
Forty-six species of Begonia are presently known from the Indonesian island of 
Sulawesi (Thomas et al., 2013), 22 of which have been described since 2006 (Hughes, 
2006; Thomas & Hughes, 2008; Girmansyah et al., 2009; Thomas et al., 2009a, 
2009b, 2011; Wiriadinata, 2013; Ardi et al., 2014). In addition, the examination 
of major herbarium collections (BO, E, L, K, SING) and specimen images from 
numerous additional herbaria provided by the Begonia Resource Centre (Hughes 
et al., 2015) indicates that there are many more species awaiting description. This 
high discovery rate is not surprising considering (i) that biological inventory rates 
and specimen collection density on Sulawesi are among the lowest in Indonesia 
(Cannon et al., 2007), (ii) the vast area (174,600 km 2 ) of the island, (iii) the markedly 
lower number of currently accepted species in comparison to the neighbouring 
Borneo: Sarawak (124,450 km 2 with c. 100 species of Begonia : Kiew et al., 2015) 
and Sabah (72,500 km 2 with 82 species: Kiew et al., 2015); Brunei (5,765 km 2 with 
22 species: Joffre et al., 2015; Low et al., 2015); and (iv) the lack of a revision of 
central Malesian Begonia. 
