Dissochaeta glandulosa Merr., Univ. Calif. Publ. Bot. 15: 224. 1929.

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

22. Dissochaeta glandulosa Merr., Univ. Calif. Publ. Bot. 15: 224. 1929. Map 15

Type.

Malaysia. Sabah: Myburgh Province, Sandakan, Oct–Dec 1921, A.D.E. Elmer 20259 (lectotype, designated here: BO [BO1421691]!; isolectotypes: BISH [BISH-1003260, image seen]!, BM [BM001190924, BM001190925]!, BR [BR00000522241, image seen]!, BRI [BRI-AQ0023052, image seen]!, C [C10014564, image seen]!, CAS [CAS0033425, image seen]!, CM [CM-1527, image seen]!, F [F65407, image seen]!, GH [GH00072204, GH00072205, images seen]!, HBG [HBG514873, image seen]!, K [K000859503]!, L [L0537261]!, MICH [MICH-1111782, image seen]!, NY [NY00228564, image seen]!, PH [PH00009602, PH00009603, images seen]!, S [SG-2104, image seen]!, U [U0124130]!).

Description.

Climbing up to 15 m in height. Branchlets terete, 3-4 mm in diameter, glabrous; nodes swollen, with crest-like interpetiolar ridge; internodes 7-11 cm long. Leaves: petioles terete, 1.3-1.8 cm long, glabrous; blades broadly ovate, 8.5-11.5 × 5.6-6.7 cm, subcoriaceous, base rounded to emarginate, margin entire, apex acuminate, tip up to 1 cm long; nervation with 1 pair of lateral nerves and 1 pair of intramarginal nerves; surfaces glabrous, basally with a pair of glandular patches on abaxially. Inflorescences terminal, up to 25 cm long, many-flowered; main axis glabrous; primary axes up to 11 cm long with 3 nodes, secondary axes 4-4.5 cm long with 1 or 2 nodes, tertiary axes ca. 2 cm long with 1 node; bracts elliptic-oblong, 20-27 × 8-10 mm, glabrous, whitish; bracteoles oblong to lanceolate, ca. 14 × 3-4 mm, glabrous, whitish; pedicels glabrous, purplish, 4-5 mm long in central flowers, 3-4 mm long in lateral flowers. Hypanthium campanulate, 5-6 × 4-5 mm, glabrous, at early stages subglobose to urceolate and enclosing petal bud; calyx lobes truncate, level, 1-2 mm long; petal bud conical, 6-7 mm long; mature petals broadly ovate, 5-6 × ca. 5 mm, base clawed, apex acute, purple above, whitish below. Stamens 8, subequal, filaments curved sideways, light yellow; alternipetalous stamens with ca. 6 mm long filaments, anthers slender, curved, sickle-shaped, thecae ca. 4 mm long, pedoconnective ca. 1 mm long, apex acute, basal crest thin, 1-1.5 mm long, margin erose to fimbriate, lateral appendages paired, filiform, 2-4 mm long, fimbriate; oppositipetalous stamens with 5-6 mm long filaments, bent at the attachment to anthers, anthers thick, slightly curved, hook-shaped, thecae 5-6 mm long, apex obtuse, yellow, basal crest thin, ligular, 2-2.5 mm long, bifid, lateral appendages paired, filiform, up to 2 mm long. Ovary half as long as hypanthium, apex villous; style ca. 14 mm long, glabrous, curved at the end, slender, light green-yellow; stigma minute, purplish; extra-ovarial chambers shallow to nearly undeveloped. Fruits urceolate, ca. 10 × 6 mm, glabrous; calyx lobe remnants persistent. Seeds ca. 0.75 mm long.

Distribution.

Borneo.

Ecology and habitat.

Lowland Mixed Dipterocarp forests on ridge at 50-400 m elevation.

Note.

Dissochaeta glandulosa resembles D. beccariana because of the similar glabrous indumentum and conspicuous white bracts. However, this species has a much larger campanulate hypanthium (5-6 × 4-5 mm in D. glandulosa , 4-7 × 2-3 mm in D. beccariana ) and urceolate fruits (subglobose in D. beccariana ).

Specimens examined.

BRUNEI. Belait: Labi, Bukit Teraja, 350 m, 18 Oct 1991, D.A. Simpson & M. Marsh 2115 (K, L). Temburong: Amo, Ulu Belalong, 480 m, 20 Jan 1994, M.J.E. Coode et al. 7864 (L). MALAYSIA. Sabah: Nabawan, Ulu Sungai Nabawan, 22 Feb 1990, Fidilis SAN 128385 (L); Penampang, Crocker Range, Kota Kinabalu–Tambunan Road, 900 m, 1 Oct 1983, J.H. Beaman & R.S. Beaman 7110 (K, L); Pensiangan, Pensiangan Kayu FR, 23 Jul 1992, Fidilis SAN 136035 (K, L); Sandakan, Myburgh, Oct-Dec 1921, A.D.E. Elmer 20259 (BISH, BM, BO, BR, BRI, C, CAS, CM, F, GH, K, L, MICH, NY, PH, S, U); Ranau, Ulu Tungud, 343 m, 27 Jul 2005, L.G. Saw et al. SAN 146062 (L); Ibid., Mount Kinabalu, Penibukan, 1200 m, 14 Mar 1931, J.Clemens & M.S. Clemens 32150 (BM). Sarawak: Betong, Batang Layar, 1 Jul 1980, B. Lee S.41990 (L); Bintulu, Bukit Pesu, Ulu Kuala Semut, 160 m, 20 Aug 1963, H.P. Fuchs 21352 (K, L); Ibid., Ulu Segan, 274 m, 25 Aug 1968, Ilias Paie S.27219 (K, L); Kapit, Belaga, Rejang River, 500 m, 31 Aug 1958, M. Jacobs 5361 (K, L), Pelagus Protected Forest, 100 m, 16 Sep 1973, P.K. Chai et al. S.33173 (BO, K, L); Ibid., Ulu Baleh, 400 m, 6 May 1991, Runi et al. S.63213 (K, L); Kuching, Selang FR., 91 m, 25 Jul 1957, Ilias Paie S.8462 (K, L); Lundu, G.D. Haviland 1508 (BM, K); Miri, Mulu, Gunung Mulu National Park, 400 m, 14 Oct 1977, P.K. Chai S.39492 (K, L). INDONESIA. Central Kalimantan: Kotawaringin Timur, Mentaya River, 50 m, 11 Feb 1994, G. Argent & P. Wilkie 9441 (L). East Kalimantan: West Kutai, Long Petah, 600 m, 10 Sep 1925, F.H. Endert 3126 (BO, K).

Figures

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