Thank you Yael for helping me solve the "crazy crocus" mystery! The flowers I have seen in my woods here look astonishingly like Crocus and they actually belong to the same family, but they are actually a variety blooming in autumn and from late summer! Hence the German name "Herbstzeitlose".
Colchicum autumnale, commonly known as autumn crocus, meadow saffron or naked lady, is a flower which resembles the true crocuses, but flowering in autumn. (This is not a reliable distinction, however, since there are many true crocuses that 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.
It is an element of the submediterranean-subatlantic flora. Its area of diffusion reaches from Southern Ireland and the Southern area of Great Britain to France, the North of the Iberian Peninsula, the Southern areas of Middle Europe and Northern Italy, to the Northern portions of the Balkan Peninsula and Western Ukraine.Autumn crocus thrives mostly on humid, rich meadows and woods -- in the latter case, preferably in sunny spots, where it is relatively warm and the plant is protected from winds.