My old apple tree has apparently become infected with Orchard Toothcrust (photo attached). The growth is in the centre of the tree, well shaded. It has been a particularly dry summer. Before I prune the limb, it was suggested to me that someone might be interested because it is an apparently rare fungus species.
Have I correctly identified the fungus?
Is anyone interested in recovering any spores? Do you have any suggestions as to how to protect my old tree?
This could well be Sarcodontia crocea (Orchard toothcrust). We are not mycologists, so cannot definitively identify the fungus for you.
The good news is that if this is orchard toothcrust fungus, it’s not a threat to the health of the tree, as it feeds on dead wood only. It colonizes dead or dry branches or can appear in cracks in bark or rotted hollows of trees, including apple. So by pruning dead wood from your lovely old tree, you should protect it from the fungus. However, it’s important to identify the fungus, as other types of fungi may weaken or harm your tree. An arborist may be able to help – Landscape Ontario provides contact information for arborists across Ontario.
Here’s a description that may also be useful in identifying the fungus: It can be over a square metre in surface area and its surface is covered with spines that point downwards, ranging from 5-17 mm in length and up to 1 mm in diameter. The fungal surface is a sulfur yellow colour initially then discolours to an ochre- to rust-brown over time. The flesh can be up to 30 mm in thickness, often with the consistency of wax. The fungus smells sweet and fruity, like pineapple or anise (one reference indicated it can smell like grated apple!). See Fungi of Great Britain and Ireland, Sarcodontia crocea for a more detailed description.
The fungus does appear to be threatened in many countries (e.g., some European countries), so experts may be interested in your specimen, and they should be able to positively identify it. I suggest that you contact the Botany faculty at your closest university. If they do not have experts in fungi on staff, they should be able to recommend someone at another university. As well, the Mycological Society of Toronto may be able to point you to experts in the field. (they also have a Facebook page)