Robust epiphyte, epilith or terrestrial. Stem to 1.3 m long. Leaves strap-shaped, to 40 cm long, to 5 cm wide, leathery, tip notched. Inflorescences to 50 cm long. Flowers non-resupinate, 15-30, to 6 cm wide, sepals green, petals and labellum white; winter. Sepals and petals similar, pointed, petals slightly narrower. Labellum broad-ovate, pointed at tip. Spur 6-8 cm long, tapering.
Several subspecies and varieties are often recognised, and these vary from the above in stem, leaf and flower characteristics.
Madagascar and neighbouring islands.
Source: (2005). Orchidaceae. In: . Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.