Dissochaeta glandiformis J.F.Maxwell, Gard. Bull. Singapore 33: 313, fig. 1. 1980.

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

21. Dissochaeta glandiformis J.F.Maxwell, Gard. Bull. Singapore 33: 313, fig. 1. 1980. Map 15

Type.

Indonesia. Jambi: Kerintji Region, Gunung Tudjuh, 1800 m elev., Jul 1956, W. Meijer 7282 (holotype: L [L0537274]!).

Description.

Climbing up to 10 m in height. Branchlets terete, 4-5 mm diameter, densely stellate-furfuraceous; nodes swollen, with annular ridge crest-like, angular or ligular interpetiolar ridges up to 5 mm wide; internodes 6-8 cm long. Leaves: petioles flattened, 10-16 mm long, densely stellate-furfuraceous; blades ovate to ovate-elliptic, 7-16 × 5-8.5 cm, membranous, base rounded, margin entire, apex acuminate, tip 0.5-2 cm long; nervation with 1 pair of lateral nerves and 1 pair of intramarginal nerves; adaxially glabrous, abaxially densely brown stellate-tomentose. Inflorescences terminal and in the upper leaf axils, up to 22 cm long, many-flowered; main axis angular, densely stellate-furfuraceous; primary axes up to 18-20 cm long with 4-5 nodes, secondary axes 2-5 cm long with 2 or 3 nodes, tertiary axes 1-2.5 cm long with 1 or 2 nodes, quartenary axis up to 0.5 cm long when developed with 1 node; bracts minute, inconspicous; bracteoles linear, 1-2 mm long, densely stellate-furfuraceous; pedicels densely stellate-furfuraceous, 4-5 mm long in central flowers, 2-3 mm long in lateral flowers. Hypanthium campanulate, slightly angular, 3-5 × 1-3 mm, with four distinct ridges, densely stellate-tomentose, somewhat pointing sideways from pedicels; calyx lobes triangular with rounded tips, 2-2.5 mm long, widened, stellate-furfuraceous; lobes in bud distinctly united in thin acorn-like shape with sutures and opening when mature; petal bud conical, 3-6 mm long; mature petals ovate or oblong, 6-9 × 3-5 mm, base clawed, apex obtuse, glabrous or inside at base with appressed hairs, pink. Stamens 4, equal, alternipetalous, filaments flat, 4-6 mm long, straight, apex bent, anthers linear-lanceolate, sickle-shaped or falcate, thecae 5-6 mm long, yellow, pedoconnective ca. 1 mm long, basal crests minute, triangular, ca. 1 mm long, narrow with acute apex, lateral appendages paired, filiform, 3-5 mm long, tan. Ovary half or ⅔ of hypanthium in length, apex pubescent; style erect, 8-13 mm long, curved at apex, glabrous, purple; stigma minute; extra-ovarial chambers 4, alternipetalous, extending to the base of the ovary. Fruits ovoid, 5-6 × 3-5 mm, glabrous to sparsely stellate-furfuraceous, rarely with distinct vertical ridges, green, often pointing sideways from the pedicels; calyx lobe remnants persistent or sometimes caducous. Seeds ca. 0.5 mm long.

Distribution.

Sumatra (West).

Ecology and habitat.

Montane forest at 900-2500 m elevation.

Note.

Dissochaeta glandiformis resembles to D. intermedia with brown stellate- tomentose hairs in leaf blades abaxiallyly and having only 4 alternipetalous stamens with two filiform lateral appendages. This species differs from the latter by having a conspicous interpetiolar ridge (annular and crest-like or ligular) at the nodes and longer calyx lobes (2-2.5 mm long). The calyx lobes are distinctly united and have an acorn-like appearance when in bud, splitting into four lobes at maturity ( Maxwell 1980b). This species is restricted to the montane forest of the Mount Kerinci complex, Sumatra.

Specimens examined.

INDONESIA. Jambi: Mt. Tujuh, 1800 m, Jul 1956, W. Meijer 7282 (L); Ibid., 6 Aug 1956, M. Jacobs 4517 (BO). West Sumatra: Mt. Kerinci, 900 m, 8 Feb 1920, H.A.B. Bünnemeijer 8074 (BO, L); Ibid., 2500 m, 7 Apr 1920, H.A.B. Bünnemeijer 9230 (BO, K, L); Ibid., 2000 m, 13 Apr 1920, H.A.B. Bünnemeijer 9379 (BO, L, U); Ibid., 1800 m, 12 May 1920, H.A.B. Bünnemeijer 10477 (BO, L).

Figures

Map 15. Distribution of D. glandiformis (●), D. glandulosa (■) and D. griffithii (▲).