Scientific name: Dendrobium kontumense Gagnep.
English name:
Vietnamese name: Hoàng mộc công tum
Other name:

Typus. — S Vietnam. Annam: entre Giang Lo et Dak To, prov. de Kontum, forêt, 500 m alt., 8.IX.1930, Poilane 18280 (holo-, P[P00408307]; iso-, C, P[P00408308]).

Habitat, phenoLogy and conservation status.

Epiphyte on  tall trees in primary and secondary evergreen and semideciduous,  broad-leaved, mixed and coniferous closed and open forests and in pine  woodlands on different kind of soils, particularly on steep rocky slopes  and along tops of hills and mountains. (200)300-1600(1700) m. Fl.  July-October.

Not common.

Expected IUCN Red List status – EN

Distribution

Laos (Borikhamxai, Khammouane, Vientiane),

Vietnam (Dak Lak, Khanh Hoa, Kon Tum, Lam Dong, Thua Thien-Hue), Thailand.

Description

Stems stout, erect, narrowly fusiform, 30-60 cm long, 1-1.5 cm  in diameter, of many nodes. Leaves elliptic to narrowly ovate,  4-8(10) cm long, 1.5-3 cm wide. Inflorescences 1-3(5), each  with (1)3-6 flowers. Pedicel and ovary 3-4 cm long. Flowers  odorless, widely opening, 4-5 cm across, white, disc red. Sepals  narrowly triangular ovate, acute, 2-2.5(3) cm long, 8-1.2 cm  wide. Petals obovate, narrowing to the base, round at apex, 2.5-3 cm long, 1.5-1.8 cm wide, twice wider than sepals, strongly  undulate along margin. Mentum narrowly conical to cylindrical,  straight or slightly curved, 2-2.5 cm long, 3 mm in diameter. Lip  pandurate, 3-lobed, 2.5-4 cm long, 1.5-2.5 cm wide; side lobes  half circular, erect; median lobe broadly obovate, 1-1.5 cm long,  1.5-2.2 cm wide, emarginate, strongly undulate and slightly  denticulate along margin; disc with 5 low insignificant rugose  keels. Column white, 5-6 mm tall (Figs 1I; 2A).

Remark

Lip coloration of D. kontumense is variable; its center bears  small or large pink, reddish, bright red or orange-red blotch. For a long time Dendrobium kontumense has been identified  in eastern Indochina by some authors as D. virgineum as pro-posed by Seidenfaden (1985). Meanwhile, true D. virgineum  described from Myanmar (“from inexhaustible Birmah, Low,  Herb. Reichenbach, 32503) distinctly differs from D. kontumense  in its broad and short mentum (Sathapattayanon et al. 2010).  Dendrobium virgineum, a rare species does not occur in Cam-bodia, Laos and Vietnam