Just before I put down my foot, I see something purple standing out against the largely still barren ground. I freeze, step back and squat down to take a closer look at the little flower - because that is what it turns out to be.
It is Liverwort (or Liverleaf) - Anemone hepatica. This member of the Buttercup family flowers in late winter or early spring and has the peculiarity that it closes its flowers in darkness and rain.
Close by I find a few more of these pretty purple flowers. This one is still half closed... because it has just rained.