Spikemoss

Yes, it covered the ground for about 20 square metres, BioEu - it really looked beautifully smooth and refreshing at once

Thanks, BioEu - I knew about that. It was just my very first impressions, since I have not seen a plant like it before. But it was obvious that it was a primal and pioneer plant, most likely a moss as I was assuming.

Thanks Jeannette - it was about palm sized, not taller than 10-15 cm. It reminded me instantly of Liverwort Mosses and somehow Horsetails came to my mind. But you're right, Thuja could have crossed the mind, too.

Thanks a lot for ID, BioEu