Dendrobium fractum

Dendrobium fractum T.M.Reeve, Orchadian 7 (1982) 133, fig. 3.

Type: Reeve 345 (holo LAE; iso K).

Robust pendulous epiphytic herb up to 2.5 m long. Roots thick, smooth, glabrous, up to 5 mm diameter. Rhizomes extremely short. Pseudobulbs cylindrical, slightly flexuous, somewhat constricted at the nodes, 10-250 by 0.8-2.8 cm, with nodes 0.4-2.7 cm apart, new stems leafy throughout, defoliated stems covered with scarious leaf sheaths, the oldest stems bare. Leaves amplexicaul, patent, ovate-elliptic to elliptic, 2-10 by 1.2-1.5 cm, upper margins crenulate, obtuse, sometimes unequally bilobed at the apex. Inflorescences arising from the nodes of defoliated stems, many-flowered in dense racemes; peduncle c. 1 cm by 7 mm; rachis c. 1.8 cm by 6 mm. Bracts papery, spathulate to diamond shaped, acute, 0.8-1.8 cm by 5-9 mm. Ovary with pedicel slightly curved, 1.9-2.4 cm long. Flowers c. 2 cm long, fleshy, glabrous, not widely opening. Dorsal sepal oblong-ovate, 0.9-1 cm by 5 mm, subacute. lateral sepals 1.5-1.8 cm by 6-7 mm. Petals ovate-elliptic, c. 0.9 cm by 4.5 mm, subacute. Lip simple, oblong-spathulate, 1.6-1.8 cm by 6 mm (expanded), basal section saccate and separated by U-shaped transverse ridge, apex obtuse and slightly reflexed. Column typical of the section, c. 4 by 4 mm; column foot 9-12 mm long; anther c. 2 by 2.5 mm; pollinia 2 mm long.
(after Reeve, 1982).

Colours: Roots with greenish to pale orange tips. Stems yellowish-green to yellow with black markings at the nodes. Flower purplish-pink (intensity varies and often the inner-flowers are paler especially the mentum), lip white with upper part golden-yellow and the apex sometimes coloured lilac. Column white, foot white with upper part golden-yellow; anther purple; pollinia purplish-grey.

Habitat: Epiphyte in montane forest, preferring shady conditions. Altitude 2100 to 2900 m.

Flowering time in the wild: May, July and November.

Distribution: New Guinea (endemic).

Distribution in New Guinea: Papua New Guinea (Southern Highlands, Enga, Western Highlands, Simbu, Eastern Highlands Provinces).

Map: FRACTMAP.JPG [Dendrobium fractum T.M.Reeve, distribution map.]

Notes: With its initially densely leafy, very long and pendulous stems Dendrobium fractum resembles a species of Agrostophyllum, although it lacks the blackish edges to the leaf sheaths commonly seen in Agrostophyllum.

Cultivation: Cool growing epiphyte. Prefers shaded position. Because of its pendulous stems best grown in a basket.