An intensively green moss can be seen along small creeks and water trickles in the Icelandic highlands, as here in the eastern part of Landmannalaugar.
I believe it's the species Takakia (Andreaeidae), but as mosses is the third most diverse group of land plants on the globe, I'm far from sure.
The diversity of mosses has been classified to approximately 10 000 species, 700 genera, and about 110-120 families.
If someone knows for sure, please drop a comment! :)