[307] Horse Chestnut Leaves July 3, 2016 by Alan Leave a comment The tree is Aesculus hippocastanum. It has Guignardia Leaf Blotch caused by the fungus Guignardia aesculi, not the bleeding canker currently affecting half the horse-chestnuts in Britain. Share this:TwitterFacebookLike Loading... Related Author: Alan Retired, currently living in Cheltenham.