Straight from Wikipedia

Colchicum autumnale, commonly known as autumn crocus, meadow saffron or naked lady, is a flower that resembles the true crocuses, but blooms in autumn. (This is not a reliable distinction, however, since many true crocuses flower in autumn.) The name "naked lady" comes from the fact that the flowers emerge from the ground long after the leaves have died back.

And then is says:

Colchicum plants have been mistaken by foragers for ramsons, which they vaguely resemble, but are deadly poisonous due to their colchicine content. The symptoms of colchicine poisoning resemble those of arsenic, and no antidote is known.

Beware. I have secret weapon in the garden.