The plant sprouts 5–11 white and non-photosynthetic leaves known as cataphylls.
These membrane-like structures cover and protect the crocus's 5 to 11 true leaves as they bud and develop.
After aestivating in spring, the plant sends up its true leaves, each up to 40 cm (16 in) in length.
Only in October, after most other flowering plants have released their seeds, do its brilliantly hued flowers develop; they range from a light pastel shade of lilac to a darker and more striated mauve. Upon flowering, the plants are 20–30 cm (8–12 in) in height and bear up to four flowers.
Saffron, long among the world's most costly spices by weight, It slowly propagated throughout much of Eurasia and was later brought to parts of North Africa, North America, and Oceania.
Saffron's taste and iodoform or hay-like fragrance result from the chemicals picrocrocin and safranal.
Each prong terminates with a vivid crimson stigma, which are the distal end of a carpel.After a period of dormancy through the summer, the corms send up their narrow leaves and begin to bud in early autumn. Harvests are by necessity a speedy affair: after blossoming at dawn, flowers quickly wilt as the day passes.One freshly picked flower yields an average 30 mg (0.0011 oz) of fresh saffron or 7 mg (0.00025 oz) dried; roughly 150 flowers yield 1 g (0.035 oz) of dry saffron threads; to produce 12 g (0.42 oz) of dried saffron, 1 kg (2.2 lb) of flowers are needed; 1 lb (0.45 kg) yields 0.2 oz (5.7 g) of dried saffron.Rain immediately preceding flowering boosts saffron yields; rainy or cold weather during flowering promotes disease and reduces yields.Persistently damp and hot conditions harm the crops, and rabbits, rats, and birds cause damage by digging up corms.