Sunday, August 4, 2013

'Crispy black stuff'

Wood decay fungi come in many shapes and sizes.  Their fruiting bodies are generally pretty easy to identify.  Mushrooms and conks along the base of a tree or attached to the trunk can be eye catching.  One commonly over looked and miss identified structural root/basal decay fungi is Brittle Cinder Fungus (Kretzchmaria deusta  formerly Ustulina deusta).  Brittle Cinder causes a soft rot that breaks down cellulose and hemi-cellulose followed by lignin.  This creates a decay that leaves wood feeling brittle.  Early stages of this decay can be hard to detect with a traditional 1/8th-inch bit and drill.

Perhaps the hardest part of identifying this decay fungi is simply noticing it.  Brittle Cinder fruiting bodies first appear as grey-white masses growing only slightly raised from the bark of the tree.  At first sight, they may be mistaken for dead lichens.  As the fruiting bodies mature, they become black and appear as burned bark.  Deusta means 'burned up.'  Unlike most common wood decay fungi, Brittle Cinder is an Ascomycota versus a Basidiomycota.

Brittle Cinder affects a vast array of tree species,including; beech, oak, maple, and linden.  Infection usually occurs through wounds in the bark.  Brittle Cinder can result in significant strength loss, so careful consideration should be taken if this fungus is located on a tree.


Here, Brittle Cinder is growing on the root flare of a red maple.  There is only 1.5-inches to 0-inches of sound wood around the affected area.