Begonia chiasmogyna M.Hughes in Edinburgh J. Bot. 63 (2-3): 193. 2006

Primary tabs

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Content

Begonia Section

  • Petermannia

Description

  • Erect softly hairy much branching herb to c.50 cm high. Stem woody at base, sometimes rooting where nodes touch substrate, densely hairy, internodes 5-13 cm.

    Stipules c.10 × 7 mm with a filiform extension at the tip, hairy, semi-persistent. Petioles 2-6 cm long, densely hairy. Leaves very asymmetric, up to 7-17 cm long from base to tip and 3-6 cm wide, midrib 5-13 cm, ovate-lanceolate, venation pinnate-palmate, covered with colourless hairs, margin scalloped and irregularly dentate with a fringe of short hairs, shallowly cordate at the base, pale green.

    Inflorescence bisexual, terminal, protogynous, female flowers occasionally borne separately; bracts ovate, c.3 mm long, fimbriate.

    Male flowers borne in monochasial cymes of c.14 flowers; tepals 2, suborbicular, c.8 × 9 mm, base cordate becoming truncate at maturity, outer surface with a few short colourless hairs, margin slightly fimbriate, white; stamens 45-50, yellow, anthers c.0.75 mm long, dehiscing through short slits near the tip, filaments the same length, slightly fused at the base.

    Female flowers borne in pairs; pedicel c.3 mm long; tepals 4, equal, sub-rhomboid, denticulate, white, c.15 × 11 mm; styles 3, twice spirally twisted, yellow, deciduous; ovary 10 × 14 mm with 3 equal wings, truncate across the apex, scattered with colourless hairs, pale green or pink, placentation axile, placentae bifid, wings rounded at the base and acute at the tip.

    Fruit c.12 × 16 mm, drying pale brown, dehiscent, capsule oval. Seeds barrel shaped, c.0.3 mm long, collar cells c.2/3 the length of the seed. (Four new species of Begonia (Begoniaceae) from Sulawesi. Edinburgh J. Bot. 63.: 191-199. 2006.)

Conservation

  • Proposed IUCN category: VU D2. (Four new species of Begonia (Begoniaceae) from Sulawesi. Edinburgh J. Bot. 63.: 191-199. 2006.)

Distribution

Asia-Tropical: Sulawesi (Sulawesi endemic)
Endemic to Indonesia, Sulawesi, Sulawesi Gorontalo.

See specimen tab for map of point distribution data of georeferenced specimens.

Etymology

  • It is unusual in section Petermannia in the female flowers having four rather than five tepals, the rhomboidal tepals giving a cross-shape to the perianth; hence the epithet chiasmogyna (female cross). (Four new species of Begonia (Begoniaceae) from Sulawesi. Edinburgh J. Bot. 63.: 191-199. 2006.)

Molecular Systematics

  • GenBank
  • see Thomas et al., 2012 (Thomas, D.C., Hughes, M., Phutthai, T., Ardi, W.H., Rajbhandary, S., Rubite, R., Twyford, A.D. & Richardson, J.E. 2012: West to east dispersal and subsequent rapid diversification of the mega-diverse genus Begonia (Begoniaceae) in the Malesian archipelago. – Journal of Biogeography 39: 98-113)

Specimens

  • Gorantalo, Nr Gunung Gambuta, 9 iv 2002, M. Mendum, H.J. Atkins, M. Newman, Hendrian, A. Sofyan 46 (E, L); Gorantalo, Gunung Boliohutu, 22 iv 2002, M. Mendum, H.J. Atkins, M. Newman, Hendrian, A. Sofyan 146 (E); Gorantalo, Gunung Boliohutu, 23 iv 2002, M. Mendum, H.J. Atkins, M. Newman, Hendrian, A. Sofyan 167 (holo E) – Type of Begonia chiasmogyna M. Hughes. (Hughes, M. An annotated checklist of Southeast Asian Begonia. 2008)