Elm Burr

Elm Burr

Observation - Elm Burr - UK and Ireland. Description: A large burr almost encircling the trunk of a young elm. Is it possible to say what has caused this? I've seen insects, fungi and viruses all blamed hence the other organisms group (which I'd be very happy to change.)

A large burr almost encircling the trunk of a young elm. Is it possible to say what has caused this? I've seen insects, fungi and viruses all blamed hence the "other organisms" group (which I'd be very happy to change.)