Gall

I've been painting the kitchen/diner all day, but escaped for an hour before tea for a bit of fresh air and a look for something to blip.
A couple of days ago I was contacted by a friend who wanted confirmation of an ID of something she has found growing from the cones of an alder tree on here smallholding. It was Alder Tongue which I had come across before but didn't realise till I researched it that it was a gall induced by a fungus. I had always thought galls were exclusively induced by insects. Just as I was talking to Roger about it on our foray yesterday, we spotted some on a nearby alder. Sometimes aspects of wildlife just seem to jump out at you, and oddly enough, I found this gall - Artichoke Gall - on a small oak tree on my afternoon walk. This one is an insect-induced one. When I researched it I was astonished to realise just how many different types of gall there are.