Orchids of New Guinea

Prev Taxon: Genus Dendrobium section Diplocaulobium subsection Mekynosepalum

Current Genus: Genus Dendrobium section Diplocaulobium subsection Regale

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Dendrobium regale

Dendrobium regale Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 476; 21 (1923) t. 161, fig. 604.

Type: Schlechter 19068 (B, lost; AMES, BM, BO, G, K, L 2x, MO, NSW, S); 19583 (B, lost).

Synonyms:

Diplocaulobium regale (Schltr.) A.D.Hawkes, Lloydia 20 (1957) 129.
Dendrobium regale Schltr. var. euanthum Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 477; 21 (1923) t. 162, fig. 605 (= var. euanthum).
- Type: Schlechter 16966 (holo B, lost).
Diplocaulobium grandiflorum Ridl., Trans. Linn. Soc. London, Bot. 9 (1916) 176.
- Type: Kloss s.n. (Camp 6b, 3900 ft.) (holo BM).
Dendrobium megalanthum Schltr., Bot. Jahrb. Syst. 58 (1923) 98 (nom. nov.).

Rhizome very short, roots elongated, filiform, flexuose, glabrous. Pseudobulbs crowded, 1-leaved, slender, to the base obclavate thickened, 40-60 by 2 (at the base) to 0.25-0.35 cm (near the apex). Leaves oblong-ligulate, 12-20 by 2.7-3.5 cm, apex obtuse, minutely bilobulate, shortly apiculate, coriaceous. Inflorescences arising in succession from the apex of the pseudobulb, 1-flowered; spathe laterally compressed, c. 2 cm long. Pedicel and ovary 5-6 cm long, slender, glabrous. Flower resupinated, c. 7 cm across. Dorsal sepal oblong-ligulate, 3.7 cm long, apex obtuse. Lateral sepals obliquely oblong-ligulate, 3.7 cm long, apex obtuse; mentum 7 mm long, obtuse. Petals obliquely elliptic, 3.7 cm long, almost twice as broad as the sepals. Lip 3-lobed above the middle, in outline very broadly rhombic, 1.2 by 1.4 cm, with two slightly diverging high keels extending from the base of the lip to the base of the midlobe; lateral lobes short, erect, rounded; midlobe broadly triangular, obtuse, apiculate. Column short, clinandrium lobulate; column-foot c. 0.7 cm long. Anther subquadrate-cucullate, truncate in front, glabrous.
(after Schlechter, 1912).

INFRASPECIFIC TAXA

Diplocaulobium regale (Schltr.) A.D.Hawkes var. euanthum (Schltr.) A.D.Hawkes, Lloydia 20 (1957) 129.

Differs from var. regale by the elongated midlobe of the lip.

Colours:

Sepals and petals deep pinkish red, the lip white with irregular purple-red stripes; column white.
Flower purple-red, midlobe of the lip light yellow; column white.

Habitat:

Epiphyte in montane forest. Altitude 700 to 2500 m.

Distribution:

New Guinea (endemic).

Distribution New Guinea:

Papua (Manokwari, Paniai, and Timika Mimika Regencies); Papua New Guinea (Southern Highlands, Enga, Western Highlands, Madang, Morobe, and Milne Bay Provinces).

Cultivation:

Intermediate growing epiphyte.

Flowering time in the wild:

January, March, April, May, September-December.

Literature:

Smith, J.J. 1916. Nova Guinea 12, 4: 297.

Notes:

Dendrobium regale Schltr. and its varieties show a remarkable variety in the morphology of the lip, as is demonstrated in the drawings given below. Also a considerable variation exists in the size of the plants. This complex is in need of revision, it may turn out that it consists of several distinct species.