I had an idea and so I started drawing.
Well, the fern didn't came out as I wanted to and since I'm "harvesting" fern for my hens over the summer, I cut of the tips.
(https://i.postimg.cc/3wvWbTLZ/mushroom-project.jpg)
Tomorrow I will get some moss and some leaves, to see, how to use them in the picture :)
The drawing looks good already. :) For the fern, you can fill the inner part of the leaves a bit.