Dissochaeta conica (Bakh.f.) Clausing in S.S.Renner et al., Fl. Thailand 7(3): 423. 2001.

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

14. Dissochaeta conica (Bakh.f.) Clausing in S.S.Renner et al., Fl. Thailand 7(3): 423. 2001. Fig. 11 , Map 10

Diplectria conica Bakh. f., Contr. Melastom.: 202. 1943.

Anplectrum crassinodum Merr., Pap. Michigan Acad. Sci. 24: 85. 1939, nom. illeg., non Merr. 1929. Type: Indonesia. North Sumatra: Asahan, Near Loemban Ria, 5-12 Apr 1934, Rahmat si Boeea 7781 (lectotype, designated by Veldkamp et al. 1979, pg. 414: MICH [MICH-1111809, image seen]!; isolectotypes: L [L0008856]!), S [SG-439, image seen]!).

Type.

Indonesia. West Sumatra: Agam, Brani, 950 m elev., 19 Jun 1918, H.A.B. Bünnemeijer 3094 (holotype: L [L0537295]!; isotypes: BO [BO1865987, BO1865988]!, L [L0537294]!).

Description.

Climbing up to 4 m in height. Branchlets terete, 4-5 mm in diameter, glabrous; nodes swollen, with raised interpetiolar ridge; internodes 4-6.5 cm long. Leaves: petioles terete, 5-10 mm long, glabrous; blades ovate to ovate-elliptic, 10-16 × 4.5-6.5 cm, subcoriaceous, base rounded, margin entire, apex acuminate, tip 0.5-1 cm long; nervation with 1 pair of lateral nerves and 1 pair of intramarginal nerves; surfaces glabrous. Inflorescences terminal and axillary, when terminal, up to 20 cm long and many-flowered, when axillary, up to 10 cm long and with 3-10 flowers; main axis angular, glabrous; primary axes up to 16 cm long with 4 or 5 nodes, secondary axes 1.5-4 cm long with 1-3 nodes, tertiary axes up to 1.5 cm long with 1 node; bracts linear, 2-4 mm long, glabrous, caducous; bracteoles linear, 1-2 mm long, glabrous; pedicels glabrous, 5-8 mm long in central flowers, 4-5 mm long in lateral flowers. Hypanthium cyathiform-tubular, cup-shaped, 7-8 × ca. 5 mm, glabrous; calyx lobes truncate, 1-2 mm long, without distinct tips or with irregularly cracked or rounded tips; petal bud conical, 5-6 mm long; mature petals ovate, 7-8 × ca. 6 mm, reflexed, white or pale purple, base clawed, apex acute. Stamens 8, unequal, filaments straight; alternipetalous stamens staminodial, with ca. 4 mm long filaments, thecae rudimentary, slender, terete, sinuate, ca. 6 mm long, basal crest oblong to triangular, ca. 1 mm long, acute at tip, thin, lateral appendages paired, ligular, ca. 1 mm long; oppositipetalous stamens with 6-7 mm long filaments, anthers thick, curved, S-shaped, thecae 9-10 mm long, connective crest bifid, erose, ca. 0.75 mm long, basal appendages paired, spur-like, ca. 1 mm long, erect. Ovary half as long as hypanthium, apex glabrous; style curved at the end, slender, ca. 15 mm long, glabrous; stigma minute, papillose; extra-ovarial chambers 4, oppositipetalous, extending almost to the base of the ovary. Fruits subglobose to urceolate, 7-8 × 5-6 mm, glabrous; calyx lobes remnant persistent, erect. Seeds ca. 0.5 mm long.

Distribution.

Peninsular Malaysia, Sumatra and Java (West).

Ecology and habitat.

Low montane forest in open places at 600-950 m elevation.

Specimens examined.

MALAYSIA. Selangor: Ulu Gombak, 15 Jun 1967, J.C. Carrick 1569 (K, L). INDONESIA. North Sumatra: Asahan, Lumban Ria, Rahmat Si Boeea 7781 (L, MICH, S); Tapanuli Selatan, Batang Toru, Telek Nauli, 885 m, 25 Mar 2004, W. Takeuchi et al. 18794 (L). West Sumatra: Agam, Brani, 950 m, 19 Jun 1918, H.A.B. Bünnemeijer 3094 (BO, L); Lima Puluh Kota, Harau Valley, Sarasah Bonta, 500 m, 11 Sep 2017, A. Kartonegoro 1078 (BO, L); Ibid., Kelok Sembilan, 800 m, 13 Sep 2017, A. Kartonegoro 1101 (BO, L). West Java: Bogor, Nanggung, Mt. Menapa, 600 m, 18 Dec 1940, C.G.G.J. van Steenis 17412 (BO, K, L).

Figures

Map 10. Distribution of D. conica (●), D. cumingii (▲) and D. densiflora (■).

Figure 11. Dissochaeta conica a habit b branchlet c hypanthium d flower e fruits. Photographs by A. Kartonegoro; vouchers: Kartonegoro 1078 (BO, L) & Kartonegoro 1101 (BO, L).