Updated: May 3, 2020
A degree of uncertainty surrounds the origin of the English word "saffron". It might stem from the 12th-century Old French term safran, which comes from the Latin word safranum, from the Arabic za'farān, which comes from the Persian word zarparan meaning "gold strung” (implying either the golden stamens of the flower or the golden color it creates when used as flavor)
The domesticated saffron crocus, Crocus sativus, is an autumn-flowering perennial plant unknown in the wild. It probably descends from the eastern Mediterranean autumn-flowering Crocus cartwrightianus which is also known as "wild saffron" and originated in Crete or Central Asia. C. thomasii and C. pallasii are other possible sources. As a genetically monomorphic clone, it slowly propagated throughout much of Eurasia.
It is a sterile triploid form, which means that three homologous sets of chromosomes make up each specimen's genetic complement; C. sativus bears eight chromosomal bodies per set, making for 24 in total. Being sterile, the purple flowers of C. sativus fail to produce viable seeds; reproduction hinges on human assistance: clusters of corms, underground, bulb-like, starch-storing organs, must be dug up, divided, and replanted. A corm survives for one season, producing via this vegetative division up to ten "cormlets" that can grow into new plants in the next season. The compact corms are small, brown globules that can measure as large as 5 cm (2 in) in diameter, have a flat base, and are shrouded in a dense mat of parallel fibres; this coat is referred to as the "corm tunic". Corms also bear vertical fibres, thin and net-like, that grow up to 5 cm (2 in) above the plant's neck.
The plant sprouts 5–11 white and non-photosynthetic leaves known as cataphylls. These membrane-like structures cover and protect 5 to 11 true leaves as they bud and develop on the crocus flower. The latter are thin, straight, and blade-like green foliage leaves, which are 1–3 mm (0.04–0.12 in), in diameter, which either expand after the flowers have opened ("hysteranthous") or do so simultaneously with their blooming ("synanthous"). C. sativus cataphylls are suspected by some to manifest prior to blooming when the plant is irrigated relatively early in the growing season. Its floral axes, or flower-bearing structures, bear bracteoles, or specialised leaves, that sprout from the flower stems; the latter are known as pedicels. 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. The flowers possess a sweet, honey-like fragrance. Upon flowering, the plants are 20–30 cm (8–12 in) in height and bear up to four flowers. A three-pronged style 25–30 mm (1.0–1.2 in) in length, emerges from each flower. Each prong terminates with a vivid crimson stigma, which are the distal end of a carpel.