Seeds from Iris crocea. The plant can reach 3 feet in height. The flowers are consisting of 3 sepals and 3 petals. Large deep golden yellow flowers, up to 12-18 cm in diameter, are borne on tall stems in June. It is an Iris with handsome upright long sword-like leaves up to 60-90 cm long. The plant spreads by means of its modified stems, rhizomes, which are located below the soil surface. zones 3 to 9