Dendrobium insigne

Dendrobium insigne (Blume) Rchb.f. ex Miq., Fl. Ned. Indië 3 (1859) 640.

Basionym: Dichopus insignis.

Rhizome short. Stems crowded, erect, rigid, in cross-section broadly elliptic, to 100 cm by 4.7 mm, many-leaved, internodes 2-2.5 cm long. Leaf sheaths tubular, as long as the internodes, longitudinally ribbed. Leaves patent, oblong-ovate, to 5.8 by 3.3 cm, apex unequally bidentate, carnose, rigid, weekly obtusely keeled below, the leaves decreasing in size upwards, in apical half of the stem very small and soon deciduous. Inflorescences arising laterally from the stem, breaking through the base of the sheath on the dorsal side, very short; peduncle 0.9 cm long, subcompressed, 2-flowered, spathe laterally compressed, broadly obtuse. Floral bracts triangular, 0.2 cm long, concave. Pedicel 0.7 cm long; ovary 0.3 cm long, 6-grooved. Flowers c. 3 cm across, lasting one or two days, fragrant. Dorsal sepal lanceolate, 2 cm by 5.3 mm, concave, apex acute. Lateral sepals oblong-triangular, angular-falcate, 1.3-1.8 cm by 9.5 mm, apex obtuse; concave, outside obtusely keeled. Petals narrowly lanceolate, falcate, 1.65 cm by 4 mm, somewhat concave, apex acute. Lip 3-lobed in basal fourth, 1.6 by 0.6 cm, inside hairy and with two prominent keels; lateral lobes small, as long as the column-foot, erect, triangular, acute; midlobe curved, narrowly elliptic, 1.1 by 0.55 cm, at the base almost claw-like narrowed, between the margins and the keels with several subulate appendages up to 2.5 mm long, decreasing in size towards the apex, apex subacute to acuminate. Column 0.4 cm long, below the stigma with an ascending, fleshy, concave lamella, which is widened at the obliquely truncate apex and extends to the apex of the column (without the anther), clinandrium denticulate; stigma quadrangular; column-foot at an acute angle to the ovary, 0.65 cm long, lightly curved, concave, papillose, obtuse. Anther cucullate, dorsally emarginate. Pollinia narrow. Fruit pendulous, oblong-ovoid, triangular, the median angle acuminate, obtuse, the lateral angles strongly winged, 4 by 1.7 cm.
(after Smith, 1909).

Colours: Sepals and petals creamy yellow with light brown tessellate blotches, lip whitish yellow with pale brown markings.

Habitat: Epiphyte in lowland forest, both seasonal and non seasonal, usually near the coast. Also in plantations. Altitude 0-700 m.

Flowering time in the wild: Several times a year, throughout the year. Flowers last about two days.

Distribution: Moluccas, New Guinea, Bismarck Archipelago, Aru Islands, Australia (Saibai Island in Torres Strait, and Queensland), Solomon Islands (Bougainville).

Distribution in New Guinea: Papua (Manokwari, Fak -Fak, and Jayapura Regencies); Papua New Guinea (Gulf, Southern Highlands (Lake Kutubu), East Sepik, Madang, Morobe, Central, Oro, and Milne Bay Provinces, also on Manus and Karkar Island, and New Britain).

Map: INSIGMAP.JPG [Dendrobium insigne (Blume) Rchb.f. ex Miq., distribution map.]

Notes: Characteristic for Dendrobium insigne are the appendage on the front of the column and the leaves that fall in two size classes: very small, early deciduous leaves on the upper part of the stem, and much larger, long-lived leaves in the middle and lower part. The leaves are thicker and more leathery than is usual in sect. Grastidium, but this species grows more exposed and is more drought resistant than most of its relatives. Dendrobium insigne is sometimes placed in a section of its own, sect. Dichopus, but considering the enormous diversity in section Grastidium we see no reason why D. insigne could not be accommodated as well.

Cultivation: Easily grown, provided it is kept warm and light throughout the year.

INFRASPECIFIC TAXA

Dendrobium insigne (Blume) Rchb.f. ex Miq. var. subsimplex J.J.Sm., Nova Guinea 8, 3 (1911) 564, pl. 92 b.

Type: Sibinga-Nijman cult. s.n. (no locality) (holo BO).

Differs from Dendrobium insigne var. insigne mainly in the shape of the lip, which has shorter and obtuse lateral lobes, and of which the midlobe lacks the elongated appendages typical for the species. The lamella on the column is shorter and broader.

Colours: Flower pale yellow, the sepals inside with two bands of red-brown spots, the petals inside with 4 broken lines of smaller red-brown spots. Lip white, inside with minute red dots, at the base yellowish with red margins and 4 red lines.

Habitat: Not recorded.

Flowering time in the wild: Not recorded.

Distribution: probably New Guinea (endemic).

Distribution in New Guinea: Not known.

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