Dissochaeta spectabilis J.F.Maxwell, Gard. Bull. Singapore 33: 321. 1980.

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

51. Dissochaeta spectabilis J.F.Maxwell, Gard. Bull. Singapore 33: 321. 1980. Fig. 26 , Map 26

Dissochaeta marumioides Furtado, Gard. Bull. Singapore 20: 111, fig. 1. 1963., nom. illeg., non Cogn. 1891.

Type.

Malaysia. Pahang: Cameron Highlands, Tanah Rata, 1300-1500 m elev., A. Johnston & M. Johnston 86 (holotype: SING!).

Description.

Climbing up to 5 m in height; branchlets terete, 3-5 mm in diameter, densely stellate-furfuraceous; nodes swollen, with interpetiolar ridge; internodes 4-5.5 cm long. Leaves: petioles flattened, 10-15 mm long, densely stellate-furfuraceous; blades ovate, ovate-elliptic or elliptic, 9-13.5 × 4.3-6 cm, membranous, base rounded to subcordate, margin entire, apex acuminate, tip 1.5-2 cm long; nervation with 1 pair of lateral nerves and 1 pair of intramarginal nerves; adaxially glabrous, abaxially densely brown stellate-tomentose. Inflorescences terminal, up to 42 cm long, many-flowered; main axis angular, densely stellate-tomentose; primary axes up to 38 cm long with 4-7 nodes, secondary axes 1.2-7.5 cm long with 1-4 nodes, tertiary axes 0.7-2.5 cm long with 1 or 2 nodes, quarternary axes when developed 0.3-0.8 cm long with 1 node; bracts linear, 8-10 mm long, densely stellate-tomentose, caducous; bracteoles linear, 5-6 mm long, densely stellate-tomentose; pedicels densely stellate-tomentose, 2-4 mm in central flowers, 1-2 mm long or subsessile in lateral flowers. Hypanthium campanulate, 7-8 × 3-4 mm, slightly 8-ridged, densely stellate-tomentose; calyx lobes triangular, 3-4 mm long, erect, apex acute, densely stellate-tomentose; petal buds conical, 8-10 × 3-4 mm, glabrous; mature petals obovate or ovate, ca. 10 × 8 mm, glabrous, reflexed, base clawed, apex obtuse, pink. Stamens 8, unequal, filaments flattened, white, base pinkish, apex yellowish, curved sideways; alternipetalous stamens with 8-10 mm long filaments, anthers lanceolate, sickle-shaped, thecae 12-14 mm long, pink, pedoconnective 3-5 mm long, basal crests distinctly triangular, ca. 1 mm long, yellow, narrow with acute apex, lateral appendages paired, filiform, 2-3 mm long, yellow; oppositipetalous stamens with 8-10 mm long filaments, anthers S-shaped, thecae 7-10 mm long, thick, cream to bright pink, basal crest spur-like, ca. 1 mm long, bifid, erect, lateral appendages paired, filiform, 2-3 mm long, brownish. Ovary ¾ of hypanthium in length, apex pubescent; style glabrous, 10-12 mm long, white, apex curved; stigma capitate, minute; extra-ovarial chambers 8, extending almost to the base of the ovary. Fruits ovoid or urceolate, 13-15 × 8-20 mm, stellate-puberulous or nearly stellate-tomentose, with calyx lobes remnant persistent to sometimes caducous. Seeds ca. 0.75 mm long.

Distribution.

Peninsular Malaysia (Pahang and Selangor) and Sumatra (West).

Ecology and habitat.

Lower to upper montane forest, in open places at 520-1740 m elevation.

Note.

Dissochaeta spectabilis can be distinguished from other species by its dense tomentose indumentum and erect, triangular, calyx lobes, which are subpersistent in fruit. The calyx lobes are remniscent of the genus Macrolenes , therefore Furtado (1963) used this as an epithet ( marumioides , like Marumia , a synonym of Macrolenes ). Since this epithet was already used by Cogniaux (1891) for a species from Sumatra, D. marumioides Furtado became a later illegitimate homonym. Therefore, Maxwell (1980b) proposed the new name of D. spectabilis .

Specimens examined.

MALAYSIA. Pahang: Bentong, 1500 m, 17 May 1987, R.D. Worthington 12804 (L); Gunung Bunga Buah, 1432 m, 4 Dec 2006, M.K. Hisham et al. FRI 52081 (K, L); Cameron Highlands, Robinson Falls, 1430 m, 30 Aug 1956, H.M. Burkill HMB 750 (K, L); Ibid., Tanah Rata, 1300-1500 m, A. Johnston & M. Johnston 86 (SING); Ibid., 1550 m, 14 Apr 1978, J.F. Maxwell 78-133 (L). Selangor: Genting Highlands, Gunong Ulu Kali, 1670 m, 17 Dec 1977, B.C. Stone 13535 (K); Ibid., 1700 m, 3 Jun 1978, J.F. Maxwell 78-323 (L, P); Ibid., 5 Aug 1979, B.C. Stone 14131 (L); Ibid., 1700 m, 11 Jun 1977, W.H. Siew 95 (L); Ibid., 1520 m, 2 Jul 1977, W.H. Siew 210 (L). INDONESIA. West Sumatra: Lima Puluh Kota, Aer Putih, 520 m, 22 Feb 1954, A.H.G. Alston 13816 (BM, BO); Ibid., Harau Valley, Sarasah Bonta, 500-580 m, 17 Apr 1999, Seren 65 (ANDA); Ibid., Kelok Sembilan, 800 m, 20 May 2001, Zul et al. 43 (ANDA); Ibid., 13 Sep 2017, A. Kartonegoro 1100 (BO, L).

Figures

Figure 26. Dissochaeta spectabilis. a habit b branchlet c hypanthium d flowers e fruits. Photographs by A. Kartonegoro; vouchers: Kartonegoro 1100 (BO, L).

Map 26. Distribution of D. sarawakensis (■), D. schumannii (▲) and D. spectabilis (●).