When we are asked for an "extreme barnwood" or an "ultra rustic barn wood," our first thought is mushroomwood.  Mushroom wood is a cool product on several fronts.
 
 

• It has a cool history.  Mushroom wood originates deep underground in Appalachian country, where many old coal and limestone mines were long ago converted into mushroom growing facilities.  A mix of cypress, hemlock and other similar species, this lumber was used to provide growing platforms for the mushrooms.  (Question:  what do mushroom wood and Bigfoot have in common?)

• It has a cool look.  Actually, it has multiple cool looks, given that (1) its back face is significantly less rustic (and significantly more consistent) than its front face and (2) different methods of processing can result in a wide range of looks (the mushroomwood in the photo at the top of this blog post, for example, was wire brushed.)

• It creates some very cool projects.  Texas lake home kitchen bar.  Wall paneling and wainscoting.  Colorado greenhouse siding.  Restaurant paneling (featuring the less rustic back face.)  Etc.

See also:  Architect Magazine feature on mushroomwood; Trestlewood email update about mushroom wood