Perennial herb, geophyte, 1.3-1.5 m high; stem slender; corm 25 mm in diam. Leaves linear, acuminate, lacerate at margins; radical leaves 600-900 x 4-8 mm; reduced sheathing leaves 3 or 4. Flowering stems 1.35-1.50 m high. Inflorescence a raceme of spikes, with 4-10 lax branches. Bracts white with pale brown streaks, 7-30 long, elliptic, acute, flecked all over and margins. Perianth blue-purple, 50-70 mm long; tube cylindrical, 15-24 mm long; tepals 33-46 x 10-16 mm, ± folded towards apex, curving outwards at maturity, dainty appearance. Anthers 8.5-11.0 mm long. Flowering time Oct.-Dec.