Grammatophyllum pantherinum Rchb.f 1878
Side View of Flower
Plant Photos courtesy of Dr. E.F. de Vogel, André Schuiteman, and Jaap Vermeulen and Their Netherlands National Herbarium Website. and Flora Malesiana Vol III
Common Name The Panther-Like Grammatophyllum
Flower Size 3.6" [9 cm]
Found in New Guinea in lowland forests at elevations of sea level to 1200 meters as a giant sized, hot to warm growing epiphyte with stout, elongated, densely leaf stems with many internodes and carrying strap-shaped, acute, midrib prominent below, coriaceous leaves that blooms in the spring and fall on a basal, stout, many flowered, to 6' 8" [2 meters] long inflorescence with triangular, obtuse, concave floral bracts and large, fleshy, fragrant flowers.
Often cited as a synonym of G speciosum but there are differences to the lip, so I leave them separate for now.
Synonyms Grammatophyllum papuanum J.J. Sm. 1911
References W3 Tropicos, Kew Monocot list , IPNI ; The Orchids of Papua New Guinea An Introduction Millar 1978 photos fide; Rudolf Schlechter Die Orchideen Band 1B lieferung 25 1520 - 1584 Brieger 1991 photo plant only ok; A Checklist of the Orchids of Borneo Wood & Cribb 1994 as G papuanum; Flora Malesiana Orchids of New Guinea Vol III Shuiteman and de Vogel 2005