Dissochaeta schumannii Cogn. in K.Schum. & Hollrung, Fl. Kais. Wilh. -Land: 88. 1889.

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

50. Dissochaeta schumannii Cogn. in K.Schum. & Hollrung, Fl. Kais. Wilh. -Land: 88. 1889. Map 26

Neodissochaeta lamiana Bakh. f., Contr. Melastom.: 142. 1943. Type: Indonesia. Papua: Prauwenbivak, Mamberamo River, 140 m elev., 29 Aug 1920, H.J. Lam 935 (holotype: L [L0537230]!; isotypes: BO [BO1747956]!, K [K000859605, K000859606]!, U [U0004013]!).

Neodissochaeta schumannii (Cogn.) M.P.Nayar, Kew Bull. 20: 160. 1966.

Type.

Papua New Guinea. Kaiser Wilhelmsland, Augusta Fluss, 1887, U.M. Hollrung 656 (lectotype, designated here: BO [BO1747958]!; isolectotypes: BR [BR5187904, image seen]!, K [K000859604]!, L [L0537229]!).

Description.

Climbing up to 4.5 m in height; branchlets terete, 3-4 mm in diameter, sparsely to densely covered with stellate hairs; nodes swollen, with interpetiolar line; internodes 7.5-8.5 cm long. Leaves: petioles terete, 8-10 mm long, stellate-furfuraceous; blades ovate to elliptic, 8-16 × 4-6.5 cm, membranous, base emarginate, margin entire, apex acuminate, tip up to 1 cm long; nervation with 1 pair of lateral nerves and 1 pair of intramarginal nerves; adaxially glabrous, abaxially with dense, stellate, brown or grey tomentose hairs. Inflorescences terminal, up to 25 cm long, many-flowered; main axis densely stellate-furfuraceous; primary axes 12-20 cm long with 4 or 5 nodes, secondary axes 3-6 cm long with 2 or 3 nodes, tertiary axes 1-2 cm long with 1 node; bracts lanceolate, 3-4 × ca. 2 mm, stellate-furfuraceous; bracteoles linear, 2-4 mm long, stellate-furfuraceous, caducous; pedicels stellate-tomentose, 3-4 mm long in central flowers, 1-2 mm long in lateral flowers. Hypanthium campanulate, 3-4 × ca. 2 mm, densely stellate-tomentose, sometimes with a few scattered, ca. 0.5 mm long glandular bristles; calyx lobes slightly triangular, ca. 4 × 2.5 mm, apex acute, densely stellate-furfuraceous, sometimes with a few glandular bristles, caducous; petal buds conical, ca. 4 mm long, glabrous; mature petals obovate, 4-5 × ca. 3 mm, base clawed, apex obtuse, glabrous, pink. Stamens 4, equal, alternipetalous, filaments curved sideways, 3-4 mm long, anthers oblong, curved, sickle-shaped, thecae 3-4 mm long, yellow, pedoconnective ca. 1 mm long, basal crest triangular with irregular edge, ca. 0.5 mm long, lateral appendages paired, filiform, 1-1.5 mm long. Ovary ¾ of hypanthium in length, apex villous; style slender ca. 5 mm long; stigma minute; extra-ovarial chambers 4, alternipetalous, shallow, ca. ¼ of ovary. Fruits globose or ovoid, 5-6 × 3-4 mm, glabrous or stellate puberulous, slightly 8-lined; calyx lobe remnants, caducous. Seeds ca. 0.5 mm long.

Distribution.

New Guinea.

Ecology and habitat.

Lowland primary forest, in open places at 90-600 m elevation.

Vernacular names.

nangumush (Waskuk); soiya (Wagu).

Note.

Different from other tetrandrous species by its distinct triangular calyx lobes which are caducous in fruit. The leaf blade underneath is also typical by the greyish tomentose indumentum, which differs from other New Guinean species (e.g. D. angiensis and D. brassii ).

Specimens examined.

INDONESIA. Papua: Camp Prauwen, Mamberamo River, 140 m, 29 Aug 1920, H.J. Lam 935 (BO, K, L); Mimika, Kuala Kencana, 65 m, 25 Jan 1998, R.J. Johns, S. Puradyatmika & A. Sadili 8887 (BO, K, L); Ibid., 10 m, 10 Apr 2000, T.M.A. Utteridge et al. 312 (BO, K, L); Ibid., 20 Nov 2000, E.J. Lucas et al. 24 (BO, K, L); Ingembit to Konomptan, 12 Jun 1967, S. Reksodihardjo 481 (BO, K, L). West Papua: Ayawasi, 450 m, 18 Mar 1996, C.E. Ridsdale 2327 (L). PAPUA NEW GUINEA. East Sepik: Ambunti, Near Wagu, 90 m, 1 Jun 1966, R.D. Hoogland & L.A. Craven 10180 (BO, K, L); Ibid., 8 Jul 1966, R.D. Hoogland & L.A. Craven 10514 (BO, K, L); Ibid., Mount Garamambu, 21 Aug 1949, J.S. Womersley NGF 3751 (BO, K, L). Milne Bay: Biniguni Airstrip, Mt. Suckling, 365 m, 5 Jul 1972, R. Pullen 8424 (BO, K, L). Morobe: Lae, Gabensis, 600 m, 25 Apr 1990, S. Simaga 1836 (L). Sepik: Kaiser Wilhelmsland, Augusta River, 1887, U.M. Hollrung 656 (BO, K, L). Western District: Kiunga, 21 m, 5 Aug 1971, H. Streimann & P. Katik NGF 46798 (BO, K, L); Ibid., Ingembit, 146 m, 13 Jun 1967, E.E. Henty, C.E. Ridsdale & M. Galore NGF 33015 (L); Bigel, 24 May 2002, P. Piskaut UPNG 20172 (K, L). West Sepik: Carpentaria, Ekwaii River, 500 m, Dec 1977, W.S. Hoover 473 (L).

Figures

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