03/23/2022
Meet Kretzschmaria deusta or Brittle cinder fungus (bad news for trees). It’s a parasitic fungus, which means it infects live trees.
This is one to watch out for. This fungus is a bit unusual in that it doesn’t look like your typical recognizable fungus – no “mushroom” here. Just grey or black crusty stuff. The grey crust with white edges is the new growth of the fruiting body of the fungus (fruiting body = what holds the spores = mushroom in some cases) and in this species typically emerges in spring and early summer. As it ages it turns darker in color, finally black and brittle – hence the name brittle cinder. In fall and winter, the evidence of infection remains as the brittle black crust.
This fungus is bad news because it degrades both of the structural components of wood: lignin and cellulose (analogy- if we think about concrete, it’s like degrading both the cement and the metal reinforcement). Trees with this infection are known for sudden collapse. It is somewhat aggressive spreading fairly quickly.
Inspect the bases, lower trunks and even branch junctions of trees for this fungus – we see it in all these locations. If you find this, move your car! or whatever else is under the tree. Contact a knowledgeable arborist to determine the urgency of tree removal. Unfortunately, there is no cure.