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Durabaculum fuscum (Fitzg.) M.A.Clem. & D.L.Jones, Orchadian 13(11): 487 (2002).
Dendrobium fuscum Fitzg. in Sydney Morning Herald 24 Sept (1879) & Gard. Chron. (new ser.), 12: 680 (1879); Dendrobium discolor var. fuscum (Fitzg.) Dockrill, Austral. Pl. 3: 28 (1964). Type: cult. ex Port Denison [Queensland], Sep. 1879, J.S. Edgar s.n. (holo not found; lectotype Fitzgerald’s unpublished plate Mitchell Library, Sydney).
Dendrobium discolor subsp. incurvata Liddle & P.I. Forst., Austrobaileya 3(2): 320, f. 1C-D (1990). Type: Queensland. Cook District: Upper Pascoe River, 12°55’S, 143°00’E, 5 July 1972, A.W. Dockrill 471 (holo QRS, iso BRI).
Occurs in north-eastern Queensland on some Torres Strait islands and from Cape York to Mackay.
Altitude: 5-250 m.
Also occurs in New Guinea.
Epiphytic or lithophytic herb forming large clumps. Pseudobulbs crowded, erect to arching, elongate, cylindrical, broadest in middle, leafy in upper two-thirds, 100-300 cm x 3-5 cm, green, becoming yellowish, hard, sheathed in papery bracts when young. Leaves 10-25, scattered along stem, erect to prostrate, distichous, alternate, sessile, bases sheathing stem; lamina ovate, 6-13 cm x 3-4 cm, dark green to yellowish, leathery, apex emarginate. Inflorescence an axillary raceme, erect to arching, 200-400 mm long, from upper nodes of stem; pedicels 20-30 mm long. Flowers 8-25, resupinate, erect to porrect, star-shaped, 30-50 mm x 30-50 mm, mainly reddish brown to dark brown, labellum often with mauve to purple markings, opening sequentially. Sepals and petals widely spreading, hardly twisted, with undulate margins. Dorsal sepal recurved, narrowly oblong, 20-25 mm x 4-5 mm. Lateral sepals widely divergent, narrowly oblong to narrowly triangular, 20-25 mm x 4-5 mm, bases fused to column foot. Petals obliquely erect, narrowly oblong to narrowly obovate, 20-30 mm x 5-8 mm. Labellum 12-17 mm x 10-14 mm, 3-lobed; lateral lobes incurved, embracing column; midlobe decurved, 4-5 mm x 2-3 mm, with 3 main undulate ridges, sometimes with accessory ridges. Column 3-6 mm. Column foot 5-12 mm. Capsules porrect to pendulous, dehiscent.
Occurs in coastal scrubs and mangroves growing on rocks and trees. Plants often have numerous aerial growths and can become very large and untidy with age. It is frequently confused with D. undulatum which has larger flowers with outcurved lateral lobes on the labellum.
Locally common.
Flowering period: April-December.
Until recently known as Dendrobium discolor var. fuscum.
