Rhizome thick, growing under water. Leaves flat, erect, to 1 m long, 1-3 cm wide with a thickened midrib. Stem 1.5 to 2 m tall, few-branched. Flowers 1-3, 8-10 cm wide, yellow; summer. Perianth tube 10-15 mm; falls spoon-shaped, about 7 cm long, often purple-veined with a deeper yellow signal; standards oblong, 2-3 cm long.

Europe.

Source: Cooke, D. (2005). Iridaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.