Plant galls are abnormal growths produced by a plant under the influence of another organism. They involve enlargement and/or proliferation of the host's cells or vascular tissue, and provide both protection and nutrition for the gall-causer (Redfern & Shirley 2011). They may be caused by insects, fungi or other organisms.

Redfern, M. & Shirley, P. (2011) British Plant Galls. FSC Publications, Preston Montford.

Sam Buckton has produced a provisional key to eriophyoid mite erinea on Acer in Britain, which has hitherto been one of the most confused situations in cecidology. The key complements the forthcoming third edition of Margaret Redfern and Peter Shirley's British Plant Galls. As well as a key, it contains an introduction to eriophyoid mite ecology and its implications for recording; extensive footnotes and lists of synonyms; and implications for verification (e.g. on iRecord).

You can download this key here