Moss.

5°C, sunny but something is changing

These things are charming.

I’m some books, mosses are categorised as primitive plants (non-vascular, and like the lichens, they don’t have roots). That means, as a group,  they’re actually very old. Their sophistication is perhaps, not visible. Internally, I suspect, they have advanced features.
They are easy plants to keep, you don’t have to ‘plant’ them, nor prune or feed them. Just leave a pot somewhere damp and then ignore it. A badly drained saucer will help. You probably have mosses growing in hidden parts of your house, most probably the gutters.
If only we could stop and look closely more often.