Scientific name: Dendrobium kontumense Gagnep.English name: Vietnamese name: Hoàng mộc công tumOther 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.
Expected IUCN Red List status – EN
Laos (Borikhamxai, Khammouane, Vientiane),
Vietnam (Dak Lak, Khanh Hoa, Kon Tum, Lam Dong, Thua Thien-Hue), Thailand.
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).
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