A synopsis of Begonia (Begoniaceae) of Southeastern Sulawesi including four new species Author Ardi, Wisnu H. Center for Plant Conservation Botanic Gardens Indonesian Institute of Sciences (LIPI), Jl. Ir. Juanda No. 13 PO. BOX. 309, Bogor 16003; wisnu.handoyo.ardi@lipi.go.id Author Chikmawati, Tatik wisnu.handoyo.ardi@lipi.go.id Author Witono, Joko R. Center for Plant Conservation Botanic Gardens Indonesian Institute of Sciences (LIPI), Jl. Ir. Juanda No. 13 PO. BOX. 309, Bogor 16003; Author Thomas, Daniel C. National Parks Board, Singapore Botanic Gardens, Research and Conservation, 1 Cluny Road, Singapore 259569; text Phytotaxa 2018 2018-12-07 381 1 27 50 http://dx.doi.org/10.11646/phytotaxa.381.1.7 journal article 10.11646/phytotaxa.381.1.7 1179-3163 13726184 8. Begonia mekonggensis Girm. & Wiriad. in Girmansyah et al. (2009: 36) ( Figures 1 & 9 ) Sect. Petermannia Type:— INDONESIA . Sulawesi , Southeast Sulawesi : North Kolaka Regency , Ranteangin District , Tinukari Village , Gunung Mekongga , 18 March 2006 , D. Girmansyah 579 ( holotype BO !; isotypes E!, K !, L, US ). Distribution:— Indonesia ; endemic to Sulawesi , so far only known from three localities (Gunung Mekongga, Mangkutana-Pendolo divide and Rantepao-Palopo divide). Habitat:— Secondary forest, at ca. 700–800 m altitude. Notes:— Begonia mekonggensis is one of several putatively dioecious species which are found in Sulawesi : B. guttapila D.C.Thomas & Ardi in Thomas et al. (2009: 234), B. rantemarioensis D.C.Thomas & Ardi in Thomas et al. (2011: 240) , B. sanguineopilosa D.C.Thomas & Ardi in Thomas et al. (2011: 243) , and B. torajana D.C.Thomas & Ardi in Thomas et al. (2011: 246) . A comparison of the salient features of Begonia mekonggensis with allied species is shown in Table 2 . TABLE 2 . Morphological comparison of Begonia mekonggensis and other putatively dioecious species from Sulawesi.

Species
Characters
B. guttapilla	B. mekonggensis	B. sanguineopilosa	B. torajana
Lamina	5–13 × 2.5–6 cm,	9–20 × 4–11 cm,	5.5–12 × 2–5 cm,	9.5–19.8 × 4.5–12
ovate to ellpitic glabrous	elliptic, glabrous	ovate to elliptc or oblong, hairy	cm, ovate to elliptic, glabrous
Male flower tepals	8–10 × 9–11 mm, elliptic to obovate	11–12 × 11–12 mm, broadly ovate to orbicular	13–19 × 14–19 mm, broadly ovate to suborbicular	11–21 × 14–19 mm, broadly ovate to suborbicular
Androecium	ca. 38–46 stamens	ca. 33–37 stamens	ca. 32–48 stamens	ca. 52–66 stamens
Ovary	8–12 × 12–15 mm ellipsoid, with characteristic hairs with bulbous base and extended tip	18–20 × 7–9.5 mm, ellipsoid, glabrous	18–20 × 7–9.5 mm, ellipsoid, hairy	18–27 × 12–15 mm, ellipsoid, glabrous
Wings	Thickened, base cuneate, apex truncate	Base rounded apex truncate	Base rounded, apex rounded or truncate	Base rounded, apex rounded or truncate
Fruits	Fleshy, indehiscent, 12–15 × 5–9 mm, ellipsoid	Dehiscent, 18–20 × 7–9.5 mm, ellipsoid	Semi-fleshy, ca. 18 × 6 mm, ellipsoid	Semi-fleshy, 15–20 × 5–7 mm, ellipsoid

FIGURE 9. Begonia mekonggensis . A. Habit, female plant; scale bar: 15 cm. B. Stipule; scale bar: 10 mm. C. Female inflorescences; scale bar 5 cm. D. Female flowers, front view; scale bar: 10 mm. E. Ovary, cross-section of middle part; scale bar: 3 mm. F. Habit, anthocyanrich form, male plant; scale bar: 10 cm. G. Male inflorescence; scale bar: 10 mm. Inset: male flower; scale bar: 10 mm. A–E from DCT 09-108 ; F–G from DCT 09-111 (Photos: D.C.Thomas). Provisional IUCN conservation assessment:— Endangered EN B2ab(iii). Begonia mekongensis is known from only a few localities including lowland rainforest in the Mangkutana-Pendolo devide and upland rainforest on Gunung Mekongga, which lie about 180 km apart. The collections from Mangkutana-Pendolo are from the periphery of a legally protected area, the Faruhumpena Forest Reserve. The small EOO ( 7,168 km 2 ) and AOO ( 28 km 2 ) in combination with only few collection localities warrant an Endangered (EN) status. Additional specimens examined:— INDONESIA . Sulawesi , Southeast Sulawesi : North Kolaka , Ranteangin District , Tinukari Village , 03 Aug. 2009 , Agus Rinai et al. AR 012 ( BO ) ; North Kolaka , Ranteangin District , Tinukari Village , 07 Aug. 2009 , A. Hidayat et al. AH 4187 ( BO ) ; North Kolaka , 19 Mar. 2006 , H. Wiriadinata et al. 588 ( BO ) ; North Kolaka , Ranteangin District , Tinukari Village , 29 June 2011 , E.A. Widjaja EAW 9693 ( BO ) .