Lichen is not one thing but two. Both fungus and algae. Not harmony, but contestation.
It grows on surfaces, this is key. It does not need soil or nutrients. But instead grows on the sacred interface of us and them. Us being the classical subject. Them being the stones and the trees.
Lichen can appear in many colours, but I prefer the colour red.
Lichen has been linked to many abnormal behaviours, for instance, some believe it causes blindness if licked, but of course this has never been tested.
Lichen when touched can cause shivers, I think this is caused by the feeling of connectives, the brainless desire not of the earth, but of the wind and the air.
Lichen is a kind of dream, so much a part of the real as to be outside of it, this is why its so deadly.
Lichen lives on other things, but does not take or give, it just exists.