Out of the Blue

 

Cobalt Crust (Terana caerulea) on a dead
Red Maple (Acer rubra) branch.
Rowan County, North Carolina. 

We have a big, old Red Maple (Acer rubra) in our front yard.  Sometimes a branch will break off and gets stuck in the canopy.  My brother calls these widow makers.  Diane decided to take down some of our widow makers, so she got out a pole saw, snagged a few, and pulled them down.  One of these branches was covered by a striking blue fungus.

I had never seen this fungus before, but its identity was revealed with just a few minutes of research.  It was Velvet Blue Spread or Cobalt Crust (Terana caerulea).  As its name suggests it is classified in the Crust Fungi that grows tightly appressed to the surfaces of dead wood. 

Cobalt Crust.
Rowan County, North Carolina. 

The body of the fungus is electric blue with white edges.  The color of Cobalt Crust is due to blue pigments called corticins.  These complex molecules require blue light for their synthesis. 

 Cobalt Crust is found in Eastern North America, Western Europe and in other scattered locations around the world. Like most Crust Fungi, Cobalt Crust is a decomposer of dead wood.  It is often found on the underside of dead limbs that have fallen to the ground.  The limb Diane pulled from the maple had been hanging vertically in the tree for some time, so the Cobalt Crust was growing on all sides of the limb. 

Cobalt Crust.
Rowan County, North Carolina. 

It is always a treat to see something new.  This fungus dropped on us, out of the blue, and was an exciting find.