By Draco
Dorset,
United Kingdom 
Sumac.
Our 18-20 ft tall Sumac has suddenly started exuding a sticky yellow resin from a host of splits in its bark. Is this an indication of something serious, please?
(Sorry, my camera's out of commission!)
R.Wyld, Dorset.
24 Jul, 2016
Answered above.
10 Aug, 2016