Tetrabaculum capitisyork (M.A.Clem. & D.L.Jones) M.A.Clem. & D.L.Jones, Orchadian 13(11): 490 (2002).
Dendrobium capitisyork M.A.Clem. & D.L.Jones, Austral. Orch. Res. 1: 49 (1989). Type: cult. ANBG, 15 July 1985, M.A. Clements 3690 ex F.M. Hill. To north of Road to Tozerís Gap, Iron Range, Queensland, 7 Sep. 1976, J.W. Wrigley 268 (holo CANB; iso BRI, K).
Dendrobium tetragonum var. giganteum P.A.Gilbert, Austral. Orchid Rev. 2(4): 19-20, 26 (Dec. 1937), nom. illeg.; 7(2): 36 (June 1942), p. p. Type: cult. Melbourne ex North Queensland, Sep.-Nov., W.H. Nicholls s.n. (type not found).
Dendrobium tetragonum var. tomentosum Nicholls, Austral. Orchid Rev. 7: 40 (Sep. 1942). Types: Kuranda, W. Fitzpatrick s.n. (syn MEL); near Cairns, F.A. Weinthal s.n. (syn MEL); Mt. Fox, via Ingham, A. Glindeman s.n. (syn MEL).
Occurs in north-eastern Queensland from Iron Range to Mackay.
Altitude: 0-900 m.
Epiphytic or lithophytic herb forming pendulous clumps. Pseudobulbs pendulous, 30-60 cm x 0.6-0.9 cm wide, narrow and wiry in basal half, becoming broader and quadrangled along length, narrowing at apex, greenish brown. Leaves 2-5, prostrate, apical, ovate, 5-9 cm x 2-4 cm, dark green, thin, leathery, apex acute. Inflorescence an axillary raceme, 10-35 mm long, from upper nodes of pseudobulb, filiform. Flowers 1-4, resupinate, porrect, 70-120 mm x 60-80 mm, greenish yellow with prominent red blotches, labellum white with red or purplish lines. Sepals narrowly triangular, tapered, apices filiform. Dorsal sepal erect, 40-70 mm x 3-5 mm. Lateral sepals divergent or sometimes crossed, falcate near base, 30-70 mm x 7-10 mm, occasionally twisted, bases fused to column foot. Petals divergent, erect, linear, 25-40 mm x 1.5-2 mm. Labellum projected forward, recurved, 11-15 mm x 17-20 mm, 3-lobed; lateral lobes erect; midlobe narrow, shortly hairy, sharply pointed, with 3 prominent parallel ridges. Column 4-5 mm long. Column foot slightly curved, 8-10 mm long, at right-angles to column. Capsules pendulous, dehiscent.
Occurs in dense rainforests and in open sites along rainforest margins growing on trees in shady sites beside streams.
Flowering period: April-November.
Until recently known as Dendrobium capitisyork or Dendrobium tetragonum var. giganteum.