Dissochaeta bakhuizenii Veldkamp, Blumea 24: 443. 1979.

Kartonegoro, Abdulrokhman, Veldkamp, Jan Frits, Hovenkamp, Peter & Welzen, Peter van, 2018, A revision of Dissochaeta (Melastomataceae, Dissochaeteae), PhytoKeys 107, pp. 1-178 : 1

7. Dissochaeta bakhuizenii Veldkamp, Blumea 24: 443. 1979. Fig. 6 , Map 5

Dissochaeta microplectrosa J.F.Maxwell, Gard. Bull. Singapore 33: 313, fig. 3. 1980. Type: Indonesia. North Sumatra: Karoland, Mount Sinabung, 1400 m elev., 19 Aug 1928, J.A. Lörzing 13673 (holotype: L [L0537283]!; isotype: BO!).

Neodissochaeta reticulata auct. non Bakh. f.: Bakh. f., Contr. Melastom.: 143. 1943. p.p., excl. type.

Dissochaeta sagittata auct. non Blume: Bakh. f., Contr. Melastom.: 233. 1943. p.p., excl. type.

Type.

Indonesia. West Sumatra: Ophir District, Tanang Taloe, 1100 m elev., 15 Jun 1917, H.A.B. Bünnemeijer 1053 (holotype: L [L0537231]!; isotypes: BO [BO1744599, BO1747935]!, PNH n.v.).

Description.

Climbing up to 30 m in height. Branchlets terete, 3-5 mm in diameter, greyish or brown stellate-puberulous with small bristle enations; nodes swollen, interpetiolar ridge distinct with collar-shaped ridge or crest-like; internodes 5-10 cm long. Leaves: petioles flattened, 10-15 mm long, stellate-furfuraceous; blades elliptic or ovate-elliptic, 7.5-13.5 × 3-5.25 cm, membranous, base rounded, margin entire, apex acuminate, tip ca. 0.5-1 cm long; nervation with 1 pair of lateral nerves and 1 pair of intramarginal nerves; adaxially glabrous, glossy green, abaxially densely, brown, short stellate-puberulous. Inflorescences terminal, up to 25 cm long, many-flowered; main axis glabrous to sparsely stellate-puberulous, rarely bristly; primary axes up to 14 cm long with 4 or 5 nodes, secondary axes up to 5 cm long with 2 or 3 nodes, tertiary axes up to 2 cm long with 1 or 2 nodes; bracts and bracteoles minute, inconspicuous, caducous; pedicels sparsely stellate-furfuraceous, 3-4 mm long in central flowers, 1-2 mm long in lateral flowers. Hypanthium campanulate-tubular, 2-5 × 1-3 mm, sparsely stellate-puberulous or nearly glabrous, somewhat 8-ridged; calyx truncate with 4 undulate lobes, widened, ca. 1 mm long, glabrous; petal bud conical, 3-5 × 2-3 mm; mature petals ovate, 4-5 × ca. 4 mm, base clawed, apex rounded, glabrous with ciliate margin, pale pink to violet. Stamens 8, equal or subequal, filaments straight; alternipetalous stamens with 4-6 mm long filaments, anthers oblong or lanceolate, straight, thecae 4-5 mm long, yellow, pedoconnective ca. 0.5 mm long, basal crests triangular with a small pair of acute auricles, 1.5-2 mm long, lateral appendages absent or prolonged from basal crest, 1-2 mm long; oppositipetalous stamens with 2.5-3 mm long filaments; anther oblong-lanceolate, straight, thecae 3-4 mm long, yellow, basal crest ligular, 1-1.5 mm long, lateral appendages a minute pair of auricles or absent. Ovary half as long as hypanthium, apex puberulous; style glabrous, curved at top, 10-12 mm long; stigma minute; extra-ovarial chambers 8, extending to the middle of the ovary. Fruits ovoid or subglobose, 4-5 × 3-4 mm, glabrous, often with 8 lines, apex mammiform; calyx lobe remnants persistent. Seeds ca. 0.4 mm long.

Distribution.

Peninsular Malaysia, Sumatra and Java (West).

Ecology and habitat.

Secondary forest, montane forest or near a crater in open forest, 700-1550 m elevation.

Vernacular names.

Sumatra: sanduduk (Batak); pulutu (Mentawai). Java: harendong areuy (Sundanese).

Note.

This species can easily be distinguished by the presence of only fertile stamens without any lateral appendages and fruits with a mammiform apex. The mammiform apex on the fruits resembles that of D. nodosa from Sumatra and D. rectandra from Peninsular Malaysia. In the indumentum of the lower leaf surface, it resembles D. inappendiculata Blume and it is sometimes misidentified when vegetative only.

Selected specimens examined.

MALAYSIA. Pahang: Cameron Highlands, Robinson’s Falls, 1600 m, 16 Apr 1978, J.F. Maxwell 78-197 (L); Ibid., 1400 m, 20 Mar 1992, J. Klackenberg & R. Lundin 673 (L); Fraser’s Hill, 1550 m, 27 Sep 1978, J.F. Maxwell 78-368 (L). Perak: Bukit Larut, Dec 1883, King’s collector 5284 (L); Ibid., Gunung Hijau, 1320 m, 13 Jul 2006, M.K. Hisham et al. FRI 52047 (BO, L). Selangor: Genting Highlands, Gunong Ulu Kali, 1200 m, 9 Apr 1978, J.F. Maxwell 78-83 (L). INDONESIA. Aceh: Mt. Leuser, Gunung Bandahara, 800-1000 m, 20 Mar 1975, W.J.J.O. de Wilde & B.E.E. de Wilde-Duyfjes 15596 (BO, K). Jambi: Kerinci, Kayu Aro, 850 m, 21 Oct 1954, W. Meijer 3007 (BO); Ibid., Sungai Kumbang, 1400 m, 4 Apr 1914, H.C. Robinson & C. Boden-Kloss s.n. (BM). Mentawai Islands: Siberut, 10 Sep 1924, C. Boden-Kloss SFN 12282 (BO, K). North Sumatra: Karo, Mount Sinabung, 1400 m, 19 Aug 1928, J.A. Lörzing 13673 (BO, L); Ibid., Road from Siantar to Berastagi, 1000 m, 21 Feb 1932, W.N. Bangham & C.N. Bangham 951 (K); Tapanuli, Between Sidikalang and Pongkolan, 1200 m, 27 Mar 1954, A.H.G. Alston 14790 (BM, BO, PNH); Prapat, Gunung Batu Lopang, 1400 m, 8 Jul 1972, W.J.J.O. de Wilde & B.E.E. de Wilde-Duyfjes 13528 (BO, K); Sibolangit, Bandar Baru, 800 m, 17 Jun 1916, J.A. Lörzing 4349 (BO); Sipirok, Dolok Sibual-Buali, 1200 m, 8 Mar 1983, Zahro 69 (BO). West Sumatra: Ophir, Tanang Talu, 1100 m, 15 Jun 1917, H.A.B. Bünnemeijer 1053 (BO, L) Lubuk Sikaping, Mt. Gadang, 700 m, 15 Jun 1953, J. van Borssum-Waalkes 1893 (BO, K); Batu Sangkar, Mount Sago, Puncak Pato, 1200 m, 10 Mar 1989, H. Nagamasu 3782 (ANDA). Banten: Between Citorek & Muncang, 800 m, 22 Jun 1911, C.A. Backer 1839 (BO). West Java: Mt. Salak, Gunung Bunder to Kawah Ratu, 1300 m, 8 Jan 1941, C.N.A. de Voogd & S. Bloembergen s.n. (BO, L); Ibid., Cangkuang, 1000 m, 16 Sep 1985, M.M.J. van Balgooy 5161 (BO, L, P); Mt. Halimun, Malasari, 1055 m, 10 Oct 2017, A. Kartonegoro 1103 (BO, L); Mt. Sembung, C.A. Backer 12256 (BO).

Figures

Map 5. Distribution of D. atrobrunnea (●), D. bakhuizenii (■) and D. barbata (▲).

Figure 6. Dissochaeta bakhuizenii. a habit b branchlet c hypanthium d flower e fruits. Photographs by A. Kartonegoro; vouchers: Kartonegoro 1103 (BO, L).