Dissochaeta densiflora Ridl., Kew Bull. 1: 32. 1946.

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

16. Dissochaeta densiflora Ridl., Kew Bull. 1: 32. 1946. Map 10

Dissochaeta rostrata Korth. var. densiflora (Ridl.) J.F.Maxwell, Gard. Bull. Singapore 33: 319. 1980.

Dissochaeta rostrata Korth. var. esetosa J.F.Maxwell, Gard. Bull. Singapore 33: 319, fig. 4. 1980. Type: Indonesia. East Kalimantan: W. Koetai, Hikam Batoe Beng, 25 m elev., 29 Jul 1925, F.H. Endert 2304 (holotype: L [L0537223]!; isotypes: BO [BO1850828]!, K [K000859632]!).

Type.

Malaysia. Sarawak: Saribas, Sungai Plandok, 19 Jul 1892, G.D. Haviland 1550 (lectotype, designated here: K [K000859631]!; isolectotype: SAR n.v.).

Description.

Climbing up to 10 m in height. Branchlets terete but angular at top part, 2-3 mm in diameter, densely covered with brown stellate-tomentose hairs and scattered short bristle hairs; nodes swollen, with interpetiolar line; internodes 7.3-14 cm long. Leaves: petioles terete, 4-10 mm long, densely stellate-tomentose and with scattered short bristle hairs; blades ovate-elliptic to elliptic, 8.3-11.5 × 3.8-6.5 cm, membranous, base emarginate, margin entire, apex acuminate, tip ca. 0.5 cm long; nervation with 1 pair of lateral nerves and 1 pair of intramarginal nerves; adaxially glabrous except stellate hairs at midrib, abaxially densely covered with brown stellate-tomentose hairs. Inflorescences terminal, up to 25 cm long, many-flowered; main axis densely covered with brown stellate-tomentose and bristle hairs; primary axes up to 20 cm long with 6 or 7 nodes, secondary axes 2.5-5 cm long with 2 or 3 nodes, tertiary axes 6-8 mm long with 1 node; bracts lanceolate or linear, ca. 7 × 1 mm, densely stellate-tomentose and with bristle hairs, caducous; bracteoles lanceolate, ca. 3.5 × 1 mm, densely stellate-tomentose outside, glabrous inside, margin with bristle hairs, caducous; pedicels brown stellate-tomentose, 2-3 mm long in central flowers, 1-1.5 mm long in lateral flowers. Hypanthium tubular, ca. 4 × 2 mm, densely brown stellate-tomentose and with scattered short bristle hairs; calyx lobes triangular, ca. 1 mm long, margin with bristle hairs, apex acute, tomentose; petal bud conical, ca. 2.5 mm long, apex bristly; mature petals ovate, 5-6 × 3-4 mm long, reflexed, base clawed, apex obtuse and bristly, rest glabrous, pale purple or purple. Stamens 8, unequal, filaments glabrous, white, curved sideways; alternipetalous stamens with 5-7 mm long filaments, anthers slender with narrow tip, curved, sickle-shaped, thecae 7-10 mm long, yellow, pedoconnective 1-1.5 mm long, basal crest triangular or ligular, 1-1.5 mm long, lateral appendages paired, filiform, 2-3 mm long; oppositipetalous stamens with 5-6 mm long filaments, anthers S-shaped, thecae 6-8 mm long, basal crest ligular, ca. 1 mm long, lateral appendages paired, filiform, ca. 2 mm long. Ovary ⅔ of hypanthium in length, apex pubescent; style curved at the end, 10-12 mm long, glabrous, white; stigma minute, light purple; extra-ovarial chambers 8, shallow or nearly to the middle of the ovary. Fruits ovoid, 5-6 × 3-3.5 mm, densely covered with stellate-tomentose hairs, sometimes becoming caducous when mature, calyx lobes persistent, reflexed. Seeds ca. 0.5 mm long.

Distribution.

Borneo.

Ecology and habitat.

Secondary forest along logging road and river banks or submontane forest at 400-1320 m elevation.

Vernacular names.

akar kemunting (Iban); lamoy puruk bawi (Dayak).

Specimens examined.

MALAYSIA. Sabah: Beluran, Bidu-Bidu Forest Reserve, 21 Jul 1970, L. Madani SAN 128874 (K, L); Lahad Datu, Danum Valley, Ulu Segama, 170 m, 25 Feb 1986, P.J. Edwards 2110 (K, L, P); Lamag, Ulu Sungai Lokan, 12 Nov 1979, Aban & Petrus SAN 90697 (K, L); Sandakan, Telupid Road, 15 Aug 1979, Aban Gibot SAN 91256 (K); Mostyn, Kalumpang Forest Reserve, 17 Feb 1966, Nordin & Ali SAN 54413 (K); Ibid., Tingkayu Camp, 180 m, 14 Sep 1966, J.Sinanggul SAN 57228 (K, L). Sarawak: Kapit, Bukit Raya, 14 Jan 1965, Jugah ak Kudi S.23863 (K); Ibid., Pelagus, 7 Jul 1979, B. Lee S.40214 (L); Ibid., Upper Rejang River, 1929, J. Clemens & M.S. Clemens 21139 (BO, K); Ibid., J. Clemens & M.S. Clemens 21569 (K); Kakus, Ulu Mayeng, 150 m, 13 Jul 1964. Sibat ak Luang S.21720 (K, L); Ibid., Tau Range, 152 m, 7 Jun 1956, J.W. Purseglove 5401 (K); Lubok Antu, Lanjak Entimau, Bukit Sengkajang, 600 m, 18 Mar 1974, P.K. Chai S.33998 (K, L); Ibid., Ulu Sg. Bengkari, 21 Mar 1974, P.K. Chai S.34082 (K, L); Miri, Gunung Mulu, 1320 m, 8 Mar 1990, P.C. Yii & Abu Talib S.58220 (L); Saribas, Sungai Plandok, 19 Jul 1892, G.D. Haviland 1550 (K). INDONESIA. Central Kalimantan: Bukit Raya, Upper Katingan River, Tumbang Samba, 150 m, 22 Dec 1982, J.P. Mogea & W.J.J.O. de Wilde 4339 (BO, K, L); Ibid., Tumbang Tubus, 150 m, 6 Jan 1983, J.F. Veldkamp 8077 (BO, L). East Kalimantan: West Kutai, Hikam Batu Beng, 25 m, 29 Jul 1925, F.H. Endert 2304 (BO, K, L); Balikpapan, Gunung Meratus, 25 Jun 2003, Arbainsyah et al. AA 3115 (BO, K, L); Ibid., Road Kenangan to Mount Meratus, 400 m, 27 Mar 1995, P.J.A. Kessler et al. 913 (K, L, P).

Figures

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