Begonia aptera Blume (1827: 97)

Ardi, Wisnu H., Chikmawati, Tatik, Witono, Joko R. & Thomas, Daniel C., 2018, A synopsis of Begonia (Begoniaceae) of Southeastern Sulawesi including four new species, Phytotaxa 381 (1), pp. 27-50 : 28-31

1. Begonia aptera Blume (1827: 97) ( Figures 1 & 2 )

Sect. Platycentrum

≡Diploclinium apterum (Blume) Miquel (1856: 691)

Type:— INDONESIA. Sulawesi: Tondano, s.coll., s.n. (lectotype L! [Herb. Ludg. Bat. 898194-39], designated by Hughes [2008]).

= Begonia cristata Warb. ex Smith & Wasshausen (1983: 442)

Type:— INDONESIA. Sulawesi, North Sulawesi: Minahasa, Tomohon, iv 1984, K.F. & P.B. Sarasin 288 (lectotype K!, designated by Smith & Wasshausen [1983]).

= Begonia renifolia Imscher (1913: 379)

Type:— INDONESIA. Sulawesi, North Sulawesi: Minahasa, Bojong, N. Wallich 15188 (holo B!).

= Begonia aptera subsp. hirtissima Girmansyah & Thomas (2009: 72) .

Type:— INDONESIA. Sulawesi, Southeast Sulawesi: Kolaka Regency, Ranteangin District, Tinukari Village, Mt. Mekongga, 21 March 2006, D. Girmansyah Deden 654 (holotype BO!, isotypes E!, L, K!, US).

Distribution:— Indonesia; widespread in E Malesia (Sulawesi, Moluccas and W New Guinea). Habitat:— Primary to secondary lowland, hill and upland forests at 200–1500 m elevation.

Provisional IUCN conservation assessment:— Least Concern (LC). Begonia aptera is widespread in eastern Malesia (Sulawesi, Moluccas and West New Guinea) and locally common in both primary and secondary forest habitats. Using GeoCAT ( Bachman et al. 2011), the species’ Extend of Occurrence (EOO) was estimated at 690,000 km 2.

Notes:— Begonia aptera is one of the most widespread Begonia species in eastern Malesia. It is part of the Begonia longifolia Blume (1823: 102) species complex ( Tebbitt 2003). Within this complex, several taxa which are morphologically similar to the type of Begonia aptera have been described ( Tebbitt 2003, Girmansyah et al. 2009). Material collected all over Sulawesi in the last 10 years shows that there are transitional forms in this morphospace, however, and we have consequently put these names in synonymy. There is considerable morphological variation between populations in Sulawesi with regard to leaf size and shape, leaf margin serration, indumentum density (glabrous to densely hairy), and fruit morphology (fruit wings clearly developed, or only present as small rims, or absent) ( Fig. 1 ). Moreover, Begonia aptera typically has three-locular ovaries and fruits, but individuals with aberrant fruit morphology (two- or four-locular fruits) have been occasionally observed in herbarium material (DCT 09-109 [BO, E]), the field and cultivation. This situation is similar to the considerable morphological variation observed in the closely related and widespread Begonia longifolia (see Hughes & Girmansyah, 2011). This species shows a very wide distribution from continental Southeast Asia to the Lesser Sunda Isles, and it has also been reported from Sulawesi. However, only two collections from Sulawesi have been cited in the literature (Johannsson et al. 76 [K] in Tebbitt [2003]; Hendrian et al. 939 [E, L] in Hughes [2008]), both of which fall in the morphological variability observed in Begonia aptera . Begonia longifolia (material from Malaysia) and B. aptera (material from Sulawesi) were retrieved as sister taxa in molecular phylogenies based on cpDNA data ( Thomas et al. 2012), and relaxed molecular clock analyses indicate that the split occurred relatively recently, in a Pleistocene timeframe (ca. 1 Ma, 95% HPD [highest posterior density interval]: 0.1–1.2 Ma). The two species are morphologically similar, and have been mainly differentiated by leaf shape and leaf margin characters (typically broadly elliptic and bidentate to -serrate in Begonia aptera ; typically lanceolate or occasionally the larger leaves broadly elliptic, margin single toothed to almost entire in B. longifolia ; see identification key in Tebbit [2003]).

Additional specimens examined:— INDONESIA. Sulawesi: Southeast Sulawesi: Mt. Watoewila , 25 Mar. 1929, G.K. Kjellberg 1032 ( BO) ; Kendari-Kolaka , 23 May 2008, A.R. Kertonegoro ARK 253 ( BO) ; Mt. Sophura, Wutamole District , 12 May 2008 D. Girmansyah Deden 859 ( BO, K) ; Mt. Pondunaah, Wutamole District , 13 May 2008, D. Girmansyah Deden 880 ( BO, K) ; Mt. Lasumowo, Mowewe District , 24 May 2008, D. Girmansyah Deden 1037 ( BO, K) ; Bite forest, Lalingato, Tirawuta Subdistrict , Kolaka , 17 July 2008 ; A. Hidayat AH 3677 ( BO, K) ; Bite forest, Lalingato, Tirawuta District , Kolaka , 17 July 2008 ; Arief Hidayat AH 3678 ( BO, K) ; North Kolaka, Rante Angin, Tinukari Village , 7 Aug. 2009. A. Hidayat et al. 4186 ( BO) ; North Kolaka, Rante Angin, Tinukari Village , 10 Aug. 2009. A. Hidayat et al. 4285 ( BO) ; Wawatobi-Lasolo road divide, 12 Feb. 2017, W.H. Ardi WI 151 ( BO, KRB, SING) ; North Kolaka, 17 Mar. 2006, H. Wiriadinata et al. 12976 ( BO). North Kolaka, Rante Angin , Tinukari Village , 20 Dec. 2009. E.A. Widjaja & Agus Suyadi EAW 8919 ( BO) ; North Kolaka, Rante Angin, Tinukari Village, 29 June 2010. E.A. Widjaja & Agus Suyadi EAW 9058 ( BO) ; North Kolaka, Rante Angin, Tinukari Village , 20 Dec. 2009. E.A. Widjaja et al. EAW 9721 ( BO) ; Mt. Pondunaa, Watuwila , 12 May 2008, A.R. Kartonegoro ARK 231 ( BO) .

Figures

FIGURE 1. Distribution map.A. Overview of Sulawesi. B. Distributions of B. aptera, B. johntania, B. mekonggensis, and B. ozotothrix.C. Distributions of B. balgooyi, B.flacca, B. matarombeoensis, and B. watuwilensis. D. Distributions of B.incudiformicarpa, B. iskandariana, and B. tumburanoensis. Specimen location information was georeferenced using the GeoNames geographical database at http://www. geonames.org/.

FIGURE 2. Begonia aptera. A. Habit; scale bar: 5 cm. B. Habit; scale bar: 5 cm. C. Inflorescence; scale bar: 1 cm D. Inflorescence; scale bar: 5 mm. E. Infructescence; scale bar: 1 cm. F.Infructescence; scale bar: 1 cm. G. Ovary, cross-section of middle part; scale bar: 5 mm. A from Ardi, W.H. 151; B, D, F, G from DCT 08-75; C from Thomas, D.C. 09-95; E from Thomas, D.C. 08-60 (Photos: A: W.H. Ardi; B-G: D.C. Thomas).