B. acclivis

Culture

Endangered Status

IUCN category EN B2a,b (iii)

Original Botanical Description or Link to

http://www.rbge.org.uk/assets/files/science/6.1_Tropical/EJB_67_123-140.pdf A Revision of Begonia section Diploclinium (BEGONIACEAE) on the Philippine Island of Palawan, incluing 5 new species - M. Hughes, C. Coyle & R. R. Rubite Rhizomatous herb, c.20 cm high. Stem 4–6 mm wide when dry, internodes c.3 mm apart, rooting at the nodes. Stipules lanceolate or broadly lanceolate, 6–10 mm long, c.6 mm wide at the base, recurved on the older parts of the rhizome, coppery brown on the reverse when dry, hairy, fimbriate towards the tip, persistent. Leaves: petiole 5–10 cm long, densely hairy, becoming less so with age, hairs brown, not appressed, c.2–3 mm long; lamina coriaceous, ovate, asymmetric, basifixed, deeply cordate to cordate at the base, lobes not overlapping or shallowly overlapping, total length 5–14 cm, width 3.5–9 cm, midrib 3.5–9 cm long, venation palmate; upper surface variegated dark and light green (always?), usually with a paler area surrounding the midrib, with evenly scattered 2 mm long hairs; underside glaucous (Pipoly & Romero et al. 37900) or red (Pipoly & Romero et al. 37782), with 2 mm long scattered hairs which are denser along the veins; margin broadly and shallowly dentate to sinuate, with short hairs more closely spaced than on the lamina, apex triangular. Inflorescence cymose, arising from the terminal nodes of the rhizome; scapes 1–7, primary peduncle up to 10–20 cm long, c.10-flowered; bracts obovate, 4 3 2 mm, margin entire, caducous. Male flower: pedicel length up to 10 mm; tepals 4, ‘white suffused with pink’ (Pipoly & Romero et al. 38029), outer tepals suborbicular, subcordate at the base, glabrous, 10 3 9 mm, margin entire, darker than the inner tepals (Pipoly & Romero et al. 37782); inner tepals obovate-spathulate, 12 3 8 mm; androecium symmetric; stamens 40–50; filaments equal, c.1.5 mm long; anther slightly shorter than the filament, oblong, dehiscing through slits the full length of the anther, connective slightly extended. Female flowers unknown. Fruit on a 15 mm long pedicel, red (Pipoly & Romero et al. 38054) drying pale brown, 15 3 15 mm in total, wings 3, upper 2 wings 5 mm wide forming a splash cup, lower wing 10–12 mm, markedly cucullate when dry, locules 2, each dehiscing along a single suture on the upper surface of the fruit, placentae bifid. Habitat and ecology. Endemic to ultramafic soils on Mt. Gantung at altitudes of c.800 m. Proposed IUCN category. EN B2a,b(iii). A considerable part of Mt. Gantung is under a mineral production agreement. Additional specimens examined. Palawan: District of Tindogan, Mantalingajan Mt. Range, Mt. Gantung, 16 viii 1996, Pipoly & Romero et al. 37782 (BRIT); ibid., 17 viii 1996, Pipoly & Romero et al. 37900 (BRIT); ibid., 19 viii 1996, Pipoly & Romero et al. 38029 (BRIT). The epithet ‘acclivis’ is derived from the Latin for uphill or steep, and refers to the habitat notes on the specimens which indicate that this species grows on ‘steep slopes which are frequently subjected to large landslides’. It differs from the two other species from Palawan which share variegated leaves and 2-locular fruit (Begonia cleopatrae and B. suborbiculata) in having broadly dentate or sinuate leaf margins and hairs on the upper leaf lamina. Begonia acclivis shows some degree of variation in leaf size and possibly variegation, although the latter character is not always preserved on herbarium specimens. One other collection 140 km to the northeast of the type locality possibly belongs here [Puerto Princesa, 20 i 1991, B.C. Stone & D.A. Madulid et al. 34 (BISH, BRIT)], but the upper leaf surface is glabrous; as circumscribed here the species is endemic to Mt. Gantung.