Tunic leathery, yellowish-brown, basal plate and neck with short hairs. Leaves 3, to 25 x 2.5 em, linear-lanceolate, channelled, erect or recurved. Flowers 1, yellow; outer perianth segments often tinged red to greenish-purple outside, 20-40 x 4.5-10 mm, narrowly elliptic, acute; inner 21-42 x 7.5-18 mm, ovate above narrow base. Filaments 6-12.5 mm; anthers 3.5-6 mm, yellow; pollen yellow. Ovary subfusiform, soon beaked. Fl. 4-5. Naturalised, 560-3000 m.
Widely naturalised in N., W., C. &S. Europe and N. Africa to Siberia and the Middle East. It is impossible to say where it is indigenous – perhaps Iran?