Orchids of New Guinea

Prev Taxon: Genus Dendrobium section Aporum subsection Crumenata

Current Genus: Genus Dendrobium section Aporum subsection Strongyle

Next Taxon: Genus Dendrobium section Biloba

Dendrobium sphenochilum

Dendrobium sphenochilum F.Muell. & Kraenzl., Österr. Bot. Zeitschr. 44 (1894) 254.

Type: Bridge & Chalmers s.n. (N. Guinea, Cloudy Mountains.) (holo HBG).

Synonyms:

Aporum sphenochilum (F.Muell. & Kraenzl.) M.A.Clem., Telopea 10, 1 (2003) 297
Dendrobium litoreum F.M.Bailey, Queensland Agric. J. 16 (1906) 411.
- Type: Copeland King s.n. (British New Guinea, Cape Nelson, Collingwood Bay).
Aporum litoreum (F.M.Bailey) M.A.Clem., Telopea 10, 1 (2003) 296
Dendrobium confusum Schltr., Repert. Spec. Nov. Regni Veg. 10 (1911) 72 (non J.J. Smith).
- Type: Schlechter 20403 (Celebes, Minahassa, Menado to Tomohon) (holo B, lost; iso AMES, L, NSW).
Dendrobium shipmanii A.D.Hawkes, Lloydia 20 (1957) 124 (nom. nov.).
Aporum shipmanii (A.D.Hawkes) Rauschert, Feddes Repert. 94 (1983) 442.
Chromatotriccum sphenochilum (F.Muell. & Kraenzl.) M.A.Clem. & D.L.Jones, Orchadian 13 (2002) 496

Rhizome short. Stems crowded, pendulous, flexuose, branching, to 60 cm by 2-4 mm, leafy throughout when young, internodes 1.5-2.5 cm long. Leaves bilaterally compressed with rounded edges, narrowly triangular-linear, often slightly curved outwards, 3-5 by 0.4-1 cm, very thick and stiff, apex acute, apiculate. Inflorescences in fascicles of 1-3 from the apex, rarely lateral from the upper part of the stem; peduncle 0.2-0.3 cm long, at the base with a cylindrical cluster of 5-6 mm long dry scales. Pedicel 0.8-1.5 cm long; ovary 0.3-0.4 cm long, conical, 6-channeled. Flowers c. 2.5 cm long. Dorsal sepal oblong, somewhat widened at the base, 0.9 cm by 4 mm, apex acute. Lateral sepals obliquely oblong, falcate, apex rounded-acute; mentum incurved, 1.5 cm long, obtuse, apex bilobed. Petals oblong, 0.9 cm by 2.5 mm, upper margin erose, apex subacute. Lip oblong, with a 5 mm long narrow basal claw, total 2.2 by 0.8 cm, on the disc with two low narrow keels terminating below the apex, margins undulate, apical margins erose, apex bilobulate, with a small apicule between the lobules. Column 0.2 cm long, filament subulate; column-foot 1.8 cm long, incurved, 2-channeled.
(after O'Byrne, 1994).

Colours:

Flower white, the keels on the lip yellow, terminating in a yellow spot near the lip apex.

Habitat:

Epiphyte in rainforest and seasonally dry forest, often overhanging rivers. Altitude 0-500 m.

Distribution:

Sulawesi, Moluccas, New Guinea, Bismarck Archipelago.

Distribution New Guinea:

Papua (Manokwari Regency); Papua New Guinea (Central and East New Britain Provinces).

Cultivation:

Warm growing epiphyte.

Flowering time in the wild:

October to April.

Literature:

Smith, J.J. 1916. Nova Guinea 12, 4: 298.
Schlechter, R. 1934. Repert. Spec. Nov. Regni Veg. Beih. 74: t. 29, fig. 113.
O'Byrne, P. 1994. Lowland Orchids of Papua New Guinea: 312, fig., pl.

Notes:

Dendrobium sphenochilum may be recognised by the elongated pendulous stems carrying laterally flattened leaves which have rounded, not sharp edges, and by the pure white flowers, usually with yellow markings on the lip.