Colchicum autumnale, commonly known as autumn crocus, meadow saffron or naked ladies, is a toxic autumn-blooming flowering plant that resembles the true crocuses, but is a member of the plant family Colchicaceae, unlike the true crocuses which belong to the family Iridaceae. The name "naked ladies" comes from the fact that the flowers emerge from the ground long before the leaves appear. Despite the vernacular name of "meadow saffron", this plant is not the source of saffron, which is obtained from the saffron crocus, Crocus sativus ń and that plant too is sometimes called "autumn crocus".
It is a perennial herb with leaves up to 25 cm (10 in) long. The flowers are solitary, 4ń7 cm (2ń3 in) across, with six tepals and six stamens with orange anthers and three white styles. At the time of fertilisation, the ovary is below ground.
Colchicum autumnale is the only species of its family native to Great Britain and Ireland, with notable populations under the stewardship of the County Wildlife Trusts. It also occurs across mainland Europe from Portugal to Ukraine, and is reportedly naturalized in Denmark, Sweden, European Russia, the Baltic states and New Zealand.
The bulb-like corms of C. autumnale contain colchicine, a useful drug with a narrow therapeutic index. Colchicine is approved in many countries for the treatment of gout and familial Mediterranean fever. Colchicine is also used in plant breeding to produce polyploid strains.
Colchicum plants are deadly poisonous due to their colchicine content, and have been mistaken by foragers for ramsons, which they vaguely resemble. The symptoms of colchicine poisoning resemble those of arsenic, and no antidote is known. This plant (and colchicine itself) poses a particular threat to felines. The leaves and fruit of meadow saffron contain the highest level of toxins,[clarification needed] but all parts of the plant are regarded as poisonous.