Dissochaeta brassii (M.P.Nayar) Karton., 2018

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

12. Dissochaeta brassii (M.P.Nayar) Karton. comb. nov. Map 8

Dissochaeta angiensis auct. non Ohwi: Veldkamp, Blumea 24: 441. 1979. p.p. excl. type.

Basionym.

Neodissochaeta brassii M.P.Nayar, Kew Bull. 20: 160. 1966.

Type.

Papua New Guinea. Milne Bay: Woodlark Island, Kulumadau, 100 m elev., 14 Nov 1956, L.J. Brass 28743 (holotype: K [K000859607]!; isotype: L [L0537255]!).

Description.

Climbing up to 10 m in height. Branchlets terete, 3-4 mm in diameter, glabrescent to densely covered with brown stellate-furfuraceous hairs; nodes swollen, with interpetiolar line; internodes 4-6.5 cm long. Leaves: petioles flattened, 1.2-1.6 cm long, densely stellate-furfuraceous; blades elliptic, 9-13.4 × 3.4-6.4 cm, membranous, base rounded or emarginate, margin entire, apex acuminate, tip 1.5-1.8 cm long; nervation with 1 or 2 pairs of lateral nerves and 1 pair of intramarginal nerves; adaxially glabrous, dark glossy green, abaxially densely brown stellate-furfuraceous, rarely rugose. Inflorescences terminal, 15-22 cm long, many-flowered; main axis densely brown stellate-furfuraceous; primary axes up to 15.5 cm long with 3 or 4 nodes, secondary axes 3-6 cm long with 2 or 3 nodes, tertiary axes 0.6-1.8 cm long with 1 node; bracts linear, 1.5-2 cm long, densely tomentose; bracteoles minute, 1-2 mm long, caducous, densely brown stellate-furfuraceous; pedicels stellate-furfuraceous, 2-3 mm long in central flowers, 1-2 mm in lateral flowers. Hypanthium tubular or funnelform, 4-6 × 2-3 mm, densely brown stellate-tomentose; calyx lobes slightly triangular, 2-2.5 mm long; petal bud conical, 5-7 × 2-3 mm, glabrous; mature petals obovate, 7-8 × ca. 4 mm, base clawed, apex rounded, glabrous, white or pale pink. Stamens 4, equal, alternipetalous, filaments straight, 5-6 mm long; anthers oblong-lanceolate, thecae 5-6 mm long, straight, yellow, pedoconnective bent, ca. 1 mm long, basal crest ligular, up to 2 mm long, lateral appendages erose or paired, filiform with irregular margin, 1.5-2.5 mm long. Ovary ⅔ of hypanthium in length, apex pubescent; style 8-9 mm long, glabrous; stigma minute; extra-ovarial chambers 4, extending to the middle of the ovary. Fruits urceolate, obpyriform, 6-8 × 5-6 mm, glabrescent; calyx remnants caducous. Seeds ca. 0.5 mm long.

Distribution.

New Guinea (Papua New Guinea).

Ecology and habitat.

On the edge of forests, secondary forest or road banks at 100-700 m elevation.

Note.

Veldkamp (1979) regards this species as a synonym of D. angiensis , which is also distributed in New Guinea and also has only 4 stamens. Dissochaeta brassii differs in having slightly triangular, 2-2.5 mm long calyx lobes, while D. angiensis has truncate, ca. 1 mm long calyx lobes. The lobes of this species will fall off when fruiting and the shape of the fruits is then sometimes similar to resembling species.

Specimens examined.

PAPUA NEW GUINEA. East Sepik: Ambunti, Waskuk Hills, 100 m, 28 Jun 1995, J.C. Regalado & W. Takeuchi 1426 (K, L). Gulf: Lakekamu, Avi Avi River, 105 m, 25 Oct 1996, W. Takeuchi & J. Kulang 11438 (K, L, P). Milne Bay: Maneau Range, Mt. Dayman, 700 m, 17 Jul 1953, L.J. Brass 23485 (L); Woodlark Island, Kulumadau, 100 m, 14 Nov 1956, L.J. Brass 28743 (K, L); Misima Island, Mt. Sisa, 21 Jul 1956, L.J. Brass 27443 (L). Morobe: Herzog Mts., above Gabensis, 680 m, 12 Jun 1991, W. Takeuchi 7040 (L); Ibid., W. Takeuchi 7040A (L); Lae, Markham Point, 240 m, 9 Jan 1963, E.E. Henty NGF 14886 (BO, K, L); Along Tymne-Wago track, 600 m, 14 Mar 1963, T.G. Hartley 11395 (K); Labu Swamp, 7 May 1990, W. Takeuchi 5668 (BO, K, L). New Britain: Kandrian, Piri Longi, 400 m, 13 Mar 1965, C.D. Sayers NGF 21952 (BO, K, L). Sepik: Lumi, Mt. Torricelli, 884 m, 22 Aug 1961, P.J. Darbyshire 247 (K, L). Southern Highlands: Lake Kutubu, near Tage, 823 m, 21 Sep 1961, R. Schodde 2189 (K, L).

Figures

Map 8. Distribution of D. beccariana (●), D. brassii (■) and D. celebica var. celebica (▲).