Corm ± 4 cm wide; tunic papery, light brown, Stems 70-100 cm high. Leaves ± ½ length of stem, to 3 cm wide, midvein slightly prominent. Spike to 25 cm long, many-flowered, occasionally branched at base; spathe-valves brown, membranous. Flowers ± 6 cm long, ± 1 cm diam., upper side scarlet, lower side yellow and green; tube 0.5 cm × 1 mm in lower narrow portion, 2 cm × 5 mm above; upper lobe 3 cm long, obtuse, scarlet, other lobes all acute, c. 5 mm long, with red lobe either side of long lobe, 3 remaining lobes green, narrower. Anthers black, projecting beyond long perianth-lobe. Seeds globose to slightly angled, orange-red, dull.