Dissochaeta angiensis Kaneh. & Hatus. ex Ohwi, Bot. Mag. (Tokyo) 57: 5. 1943.

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

3. Dissochaeta angiensis Kaneh. & Hatus. ex Ohwi, Bot. Mag. (Tokyo) 57: 5. 1943. Map 2

Type.

Indonesia. West Papua: Arfak Mts., track to Lake Gita from Momi, 1300 m elev., 4 Apr 1940, R. Kanehira & S. Hatusima 13374 (lectotype, designated here: FU n.v.; isolectotype: L [L0537256]!).

Description.

Climbing up to 7 m in height. Branchlets terete, 3-6 mm in diameter, covered with densely stellate-furfuraceous hairs, rarely pubescent; nodes swollen, interpetiolar ridge slightly raised; internodes 5-12.3 cm long. Leaves: petioles terete, 10-17 mm long, densely stellate-furfuraceous; blades ovate, elliptic to oblong, 8.2-18 × 4-7 cm, membranous to nearly subcoriaceous, base rounded or emarginate, margin entire, rarely subserrulate, apex acuminate, tip 1-1.5 cm long; nervation with 1 (rarely 2) pairs of lateral nerves and 1 pair of intramarginal nerves; adaxially glabrous, dark glossy green, abaxially brown stellate-furfuraceous, dense on midrib. Inflorescences terminal and in the upper leaf axils, many-flowered, up to 57 cm long; main axis angular, densely stellate-furfuraceous; primary axes up to 54 cm long with 6-8 nodes, secondary axes up to 18.5 cm long with 1-3 nodes, tertiary axes 1-4 cm long with 1 or 2 nodes or sometimes undeveloped; bracts linear, ovate or elliptic, 1.7-3.5 × ca. 1.2 cm long, densely brown stellate-furfuraceous, caducous; bracteoles linear, 1-2 mm long, densely stellate-furfuraceous, caducous; pedicels densely stellate-furfuraceous, 3-4 mm long for central flowers, 2-3 mm long for lateral flowers. Hypanthium urceolate, 4-5 × 2-2.5 mm, densely stellate-furfuraceous; calyx lobes truncate with 4 triangular tips, ca. 1 mm long; petal buds conical, 3-4 mm long, blades ovate, base clawed, apex acute; mature petals oblong, 7-9 × 4-6 mm, base clawed, margin ciliate, apex obtuse, glabrous, white to pinkish. Stamens 4, equal, alternipetalous, filaments straight; alternipetalous stamens with 5-7 mm long filaments, anthers oblong or lanceolate, thecae slightly straight, 5-6 mm long, yellow, pedoconnective short or slightly undeveloped, basal crest hastate or triangular, 0.75-1 mm long, lateral appendages ligular, ribbon-like or paired and filiform with irregular margins, 0.75-2 mm long. Ovary ¾ of hypanthium in length, apex villous; style 10-12 mm long, glabrous; stigma capitate, minute; extra-ovarial chambers 4, shallow, extending ca. ⅓ of ovary. Fruits ovoid-urceolate, 5-8 × 2.5-7 mm, glabrous to glabrescent, green when young, calyx remnants persistent, widened. Seeds ca. 0.5 mm long.

Distribution.

Moluccas and New Guinea.

Ecology and habitat.

Lowland hill forest to lower montane forest at 50-1300 m elevation.

Vernacular names.

Moluccas: siri utan (Ambon); arendong (Bacan). New Guinea: tsoin (Kutubu); johnihoeveke (middle Waria).

Note.

Dissochaeta angiensis resembles D. celebica Blume but differs by having a much larger urceolate hypanthium and short lateral appendages (0.75-2 mm) on the alternipetalous stamens. The mature anthers are straight rather than curved.

Specimens examined.

INDONESIA. Moluccas: Bacan, Mt. Damar, Masurung, 200 m, 12 Aug 1937, Nedi 28 (BO); Ceram, Honitetu–Wae Tuba, 4 Feb 1938, P.J. Eyma 2771 (BO, L); Ibid., Between Raniki and Manusela, 1000 m, 24 Jun 1918, Kornassi 1403 (BO). North Moluccas: Halmahera, Mt. Sembilan, 600 m, 28 Sep 1951, D.R. Pleyte 299 (BO, K, L, PNH); Morotai, Mt. Pare-Pare, Rawa Panjang, 1000 m, 28 May 1949, A.J.G.H. Kostermans 1322 (BO, K, L, PNH). West Papua: Vogelkop Peninsula, Ije River Valley, Bamfot Village, 850 m, 2 Nov 1961, P. van Royen & H. Sleumer 7646 (BO, K, L); Ibid., Isjon River Valley, Son Village, 650 m, 28 Oct 1961, P. van Royen & H. Sleumer 7574 (BO, K, L); Arfak Mountains, Angi, 1300 m, 4 Apr 1940, R. Kanehira & S. Hatusima 13374 (L); Bomberai Peninsula, Tangguh, 50 m, 21 Feb 2002, W. Takeuchi, E.N. Sambas & R. Maturbongs 16004 (BO). PAPUA NEW GUINEA. Central Division: Sogeri, Subitana, 22 Jun 1954, J.S. Womersley & P. van Royen NGF 5815 (BO, K), Ibid., 1885, H.O. Forbes 459 (BM). Chimbu: Haia, 640 m, 16 Sep 1996, W. Takeuchi 11200 (K). East Sepik: Waskuk Hills, between Garuka and Waskuk, 60 m, 28 Jun 1995, W. Takeuchi & J.C. Regalado 10198 (L). Madang: Bismarck Range, Gulno Village, 1050 m, 15 Oct 1995, W. Takeuchi 10790 (L). Morobe: Kipu, Tiaura, 800 m, 7 Jan 1966, H. Streimann NGF 26113 (BO, K, L); Wampit, Bupu Village, 760 m, 3 Mar 1964, A.N. Millar NGF 23243 (L); Ibid., 1310 m, 13 Jul 1967, A.N. Millar NGF 22928 (L); Wareo, 600 m, 25 Dec 1935, J. Clemens & M.S. Clemens 1395 (L). Southern Highlands: Tari, Bosavi Mission-Mulimia Govt. Stn., 700 m, 2 Sep 1986, O. Gideon LAE 57470 (K, L).

Figures

Map 2. Distribution of D. acmura (●), D. alstonii (■) and D. angiensis (▲).