1. Family: Begoniaceae C.Agardh
    1. Genus: Begonia L.
      1. Begonia mentewangensis Girm.

        This species is accepted, and its native range is Borneo (Kalimantan).

    [KBu]

    Girmansyah, D. & Susanti, R. 2015. Two new species of Begonia (Begoniaceae) from Borneo. Kew Bulletin 70: 19. DOI https://doi.org/10.1007/s12225-015-9569-6

    Type
    Type: Indonesia, Central Kalimantan, PT Sari Bumi Kusuma (SBK) Katingan-Seruyan logging concession area, Mentewang hill entered from Km 87 Forest logged in 2000, S00°57'32.5"" – 31.5"", E112°21'32.2"" – 28.8"", c. 283 m alt., 16 Nov. 2011, Deden 1548 (holotype BO!, isotype BO!).
    Habit
    Erect, hairy herb, up to 60 cm tall
    Stem
    Stem woody at base and fleshy near the apex, swollen at nodes, rooting at the nodes, internodes 2 – 7.5 cm apart, shorter nearer the apex, with dense long hairs near to the apex of the stem, becoming glabrous with age near the base, reddish brown
    Stipules
    Stipules widely to narrowly triangular, with scattered hairs along the dorsal midvein, with a hair-like appendage at the apex, 0.9 – 1 × 0.4 – 0.5 cm, caducous
    Leaves
    Leaves alternate; petioles 0.7 – 1 cm long, sparsely to densely hairy; lamina 15 – 17 × 5 – 10 cm, slightly asymmetric, elliptic-oblong, base unequal, cuneate at one side and rounded the other side, one side extending 4 – 5 mm further down the petiole than the other, broad side 3 – 4.5 cm wide, narrow side 2.5 – 4 cm wide, apex acute to acuminate, margin biserrate with minute hairs at the end of each tooth, upper surface dark green with scattered short hairs on the main vein and between the vein, underside pale green with scattered reddish hairs along the veins, venation pinnate, 8 – 9 pairs, two pairs nearest the base arising opposite, remaining pairs alternate
    Inflorescences
    Inflorescence racemes, peduncle 2 – 4 cm long, male and female flower on the same inflorescences, male flower distal with many flowers and female flowers basal in pairs
    Flowers
    Female flowers: pedicels c. 0.3 cm long; tepals 5, unequal, biggest 0.5 × 0.9 cm, smallest 0.3 × 0.6 cm; ovary capsule c. 0.6 – 0.7 × 1 cm, ovoid, locules 3, placentation axile, placentae 2 per locule; wings 3, equal, rounded at the apex, 2 mm wide, stigmas 3, style Y-shaped, 2.5 mm long Male flowers: pedicels 0.4 – 1 cm long, hairy; tepals 2, white with scattered short red hairs on dorsal side, 0.4 – 0.5 × 0.5 – 0.6 cm, rounded to obovate; androecium 0.2 – 0.25 cm diam., cluster globose, stamens c. 20, filaments c. 1 mm long, fused at the base, anthers c. 2 mm long, oblong, dehiscing through unilateral slits c. ½ as long as anther
    Fruits
    Fruit: pedicel red hairs, 0.6 – 0.8 cm long; fleshy-walled capsule, ovoid, covered in fleshy bristles, 1 – 1.2 × 0.5 – 0.7 cm, with 3 equal wings, wings 3 mm wide at the widest point, thick fibrous, 2.5 – 4 mm wide, splitting between the locules and wings
    Seeds
    Seed ovoid, 0.32 – 0.34 mm long, collar cells more than half of the seed length
    Note
    Related to Begonia antonyiKiew, differing in the leaf shape (elliptic to oblong, not slightly falcate); number of veins 8 – 9 pairs (vs veins 6 – 7 pairs in B. antonyi); the fruit (ovoid and covered in fleshy bristles, not broadly deltoid and glabrous). The bristly fruit resembles that of B. guttapila D. C. Thomas & Ardi, covered by bristles but is on a longer pedicel (0.6 – 0.8 cm vs 0.1 – 0.2 cm in B. guttapila); and the widest point of the wing is 2.5 – 4 mm (vs 6 – 9 mm). The species is named after the type locality Mentewang hill in West Kalimantan. Begonia mentewangensisis a very distinctive species in section Petermannia with short hairy petioles, lamina with slightly asymmetric leaves and a fleshy-walled capsule. The upper surface of the leaves is dark green with scattered short hairs on the main vein and between the veins, and the undersurface pale green with scattered reddish hairs along the veins.
    Distribution
    Only known from two locations in Borneo, km 87 in Mentewang Hill and km 67 in PUP5 Further explorations are necessary to ascertain the status of the species. A preliminary conservation status of Data Deficient (DD) seems appropriate (IUCN 2001).
    Ecology
    Terrestrial or sometimes lithophytic herb on thick humus on rock surfaces in mixed lowland and hill Dipterocap forest, frequently along the stream margin in wet and damp places, alt. 300 m.
    Conservation
    Begonia mentewangensis is known from two localities about 20 km apart. It is likely to be found in other similar habitat in Borneo and more extensive collections from the region are needed to confirm its

    Distribution

    Begonia mentewangensis Girm. appears in other Kew resources:

    First published in Kew Bull. 70(2)-19: 1 (2015)

    Literature

    Kew Bulletin
    • Julia, S., Kiew, R. & Geri, C. (2013). Revision of Begonia (Begoniaceae) from the Melinau Limestone in GunungMulu National Park and Gunung Buda National Park, Sarawak, Borneo, including thirteen new species. Phytotaxa 99(ser. 1): 1 – 34.Google Scholar
    • Kiew, R. & Julia, S. (2009). Seven new species of Begonia (Begoniaceae) from the Ulu Merirai and Bukit Sarang Limestone Areas in Sarawak, Borneo. Gard. Bull. Singapore 60 (2): 351 – 372Google Scholar
    • Hughes, M. (2008). An Annotated Checklist of South-East Sulawesi Asian Begonia. Royal Botanic Garden, Edinburgh.Google Scholar
    • Kiew, R. & Julia, S. (2007). Begonia (Begoniaceae) from Limestone Hills in the Kuching Division, Sarawak, Malaysia. Gard. Bull. Singapore 58 (2): 199 – 232.Google Scholar
    • Kiew, R. (2005). Begonia in Peninsular Malaya. Natural History Publications, Borneo.Google Scholar
    • IUCN (2001). IUCN Red List Categories and Criteria: Version 3.1. Prepared by IUCN Species Survival Commission, IUCN, Gland and Cambridge.Google Scholar
    • Doorenbos, J., Sosef, M. S. M. & De Wilde, J. J. F. E. (1998). The sections of Begonia including descriptions, keys and species lists (Studies in Begoniaceae VI). Wageningen Agr. Univ. Pap. 98(2): 1 – 266.Google Scholar

    Sources

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Bulletin
    Kew Bulletin
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0