Amanita symbiosis system

 As Mushrooms Evolve to Live With Trees, They Give Up DNA Associated With Decomposing Cellulose
ScienceDaily (July 18, 2012)
"...if you're going to actively form a cooperative relationship with a tree, you probably shouldn't simultaneously be trying to break it apart and eat it. But it's a very tricky dance to form these kinds of tight, cooperative interactions, and I think this work shows there is a cost associated with that. You have to change, you have to commit, and it can become a sort of gilded cage -- these mushrooms are very successful..." --http://www.sciencedaily.com/releases/2012/07/120718192047.htm