In Design: what can I use for this effect

I can not identify the wood or rock on the back wall in the link below. I would like to find away to mount moss or nana anbias up on the wall, without taking up a lot of space. Have any other Idea's on how I could do this and get a shelf look?

I like the look in the pictures at the bottom, when they are not grown in so much. In "Tank" it says's its roots could that be right?

galeria

 

You are very right about the cork. I saw Tom's wood collection today and he has perfect strips of raw cork that would look cool and not take up much room. I forgot about raw all I could picture was the panels we used in the 60's to sound proof or some did hole wall with mirrors strips in between.