Begonia masarangensis Irmsch. in Bot. Jahrb. Syst. 50(4): 368. 1913

Primary tabs

https://drive.google.com/uc?id=1cGKndQalicLgBFdc6LdWYUIwwOQ2qOnP

Content

Begonia Section

  • Petermannia

Description

  • Perennial, small, monoecious herb, erect, c.20–25 cm tall. Stem erect, few-branched; internodes 1–4 cm long, slightly swollen at the nodes, brownish-reddish, densely hairy with bristly hairs. Leaves basifixed, alternate; stipules persistent, 5–8 × 2.5–4.5 mm, anisophyllus, ovate, with an abaxially slightly prominent midrib, apex narrowed into bristle projecting up to 6 mm, margin entire, cream-coloured, abaxially hairy; petioles 0.6–3 cm long, terete, not channelled, concolorous with the stem, densely hairy; lamina 3.7–9.5 × 2.5–4.5 cm, asymmetrical, elliptic, base cordate and lobes not or just slightly overlapping, apex acuminate, margin biserrate, adaxial surface green, with red veins, densely covered with strigose, simple or sometimes branched hairs, abaxial surface brownish, hairy; venation pinnate, secondary veins craspedodromous. Inflorescences protogynous, female inflorescences basal to male or sometime solitary; female inflorescences 1-flowered, peduncles c.10 mm long, bract persistent, c.5 × 1–2 mm, elliptic; male inflorescences simple monochasia with up to 10 flowers, peduncle c.6 mm, hairy, bracts caducous. Male flowers: pedicels 9–16 mm long, white-cream, hairy; tepals 2, white, 12–17 × 17–22 mm, broadly ovate, base slightly cordate, apex rounded, outer surface hairy; androecium of 22–25 stamens, yellow, filaments up to c.1 mm long, slightly fused at the very base, anthers up to c.1 mm long, oblong to narrowly obovate, dehiscing through unilaterally positioned slits that are c.1/2 as long as the anthers. Female flowers: pedicels c.7 mm long, pink, densely hairy; tepals 5, white, unequal, four larger c.15 × 17 mm, broadly ovate, one smaller 12–15 × 5–10 mm, obovate, adaxially hairy; ovary (excluding wings) 8 × 4.5 mm, ellipsoid, pale green with red longitudinal line, densely hairy, locules 3, placentation axile, placentae bilamellate, wings 3, subequal to unequal, pale green, base rounded, apex truncate, up to 9 mm at the widest point (apically or subapically); style c.6 mm long, basally fused, 3-branched, each stylodium bifurcate in the stigmatic region, stigmatic surface a spirally twisted papillose band, orange. Fruits not seen. (Ardi, W.H. & Thomas, D.C. 2022: Synopsis of Begonia (Begoniaceae) from the northern arm of Sulawesi and Sangihe Island, Indonesia, including three new species. – Edinburgh J. Bot. 79(Begonia special issue, article 405): 1-50)

Habitat & Ecology

  • Disturbed or secondary upland to montane forest at 1000–1800 m elevation, in full shade. (Ardi, W.H. & Thomas, D.C. 2022: Synopsis of Begonia (Begoniaceae) from the northern arm of Sulawesi and Sangihe Island, Indonesia, including three new species. – Edinburgh J. Bot. 79(Begonia special issue, article 405): 1-50)

Conservation

  • IUCN category: DD. Taxonomic uncertainty. (Hughes, M. An annotated checklist of Southeast Asian Begonia. 2008)
  • Critically Endangered (CR), B1ab(iii)+B2ab(iii). Begonia masarangensis is known from only two collections from a small forest remnant at its type locality, Gunung Masarang, Tomohon. The area is not legally protected, and currently most of the forest formerly surrounding the type locality has been converted into agricultural land. In combination with the very small AOO (4 km2), this indicates that the species should be considered Critically Endangered (IUCN Standards and Petitions Subcommittee, 2019). (Ardi, W.H. & Thomas, D.C. 2022: Synopsis of Begonia (Begoniaceae) from the northern arm of Sulawesi and Sangihe Island, Indonesia, including three new species. – Edinburgh J. Bot. 79(Begonia special issue, article 405): 1-50)

Distribution

Indonesia: endemic to Sulawesi, North Sulawesi Province (eastern North biogeographical region), Gunung Masarang

See specimen tab for map of point distribution data of georeferenced specimens.
See images for distribution map. (Ardi, W.H. & Thomas, D.C. 2022: Synopsis of Begonia (Begoniaceae) from the northern arm of Sulawesi and Sangihe Island, Indonesia, including three new species. – Edinburgh J. Bot. 79(Begonia special issue, article 405): 1-50)

Notes

  • Koorders (1904) cited two specimens: Koorders 16240b from Gunung Masarang, and Koorders 19241b, presumably from Gunung Lolomboelan. The latter was designated as lectotype for Begonia hispidissima by Smith and Wasshausen (1983). The former conforms with Begonia masarangensis, which based on morphology (see respective Image tabs) and DNA sequence data (Thomas et al., 2012), is distinct from Begonia hispidissima. [Note by D.C.Thomas; 1/8/2013]
  • Begonia hispidissima is similar to B. masarangensis in its dense indumentum on the stems and leaves, and the elliptic leaves with serrate to biserrate margin. However, it can be differentiated by several characters such as the male inflorescence thyrse consisting of 2 or 3 partial cymose inflorescences (vs male flowers in simple monochasia) and 2-flowered female inflorescences with 8–12 mm long pedicels (vs 1-flowered with pedicels ≤ 7 mm long). (Ardi, W.H. & Thomas, D.C. 2022: Synopsis of Begonia (Begoniaceae) from the northern arm of Sulawesi and Sangihe Island, Indonesia, including three new species. – Edinburgh J. Bot. 79(Begonia special issue, article 405): 1-50)

Molecular Systematics

  • 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)
  • GenBank
  • see Thomas et al., 2011 (Thomas, D.C., Hughes, M., Phutthai, T., Rajbhandary, S., Rubite, R., Ardi, W.H. & Richardson, J.E. 2011: A non-coding plastid DNA phylogeny of Asian Begonia(Begoniaceae): Evidence for morphological homoplasy and sectional polyphyly. – Molecular Phylogenetics and Evolution 60: 428-444)

Specimens

  • Indonesia. Sulawesi. Northern arm of Sulawesi. Eastern North Sulawesi: Minahassa, top of G. Masarang, 10 i 1949, Koorders 16240b (K); 20 ii 2008, M. Ardiyani, A.D. Poulsen & Ale 105 (BO); 2 ii 2019, W.H. Ardi et al. WI400 (BO, FIPIA). (Ardi, W.H. & Thomas, D.C. 2022: Synopsis of Begonia (Begoniaceae) from the northern arm of Sulawesi and Sangihe Island, Indonesia, including three new species. – Edinburgh J. Bot. 79(Begonia special issue, article 405): 1-50)