What's causing the growths on the underside of these oak leaves?
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The smaller spangle galls are caused by Neuroterus quercusbaccarum, which is a cynipid wasp, the same family as the Apple Gall one.
It's quite pissoble you'd have found Knopper Galls on the acorns as well - they seem quite prevelent on the good acorn crop this year.
...the large rounded gall looks more like a cherry gall, caused by Cynips quercusfolii.
Oak apples have long since disappeared by August.
Cherry galls usually form on the underside of the leaves and can be coloured green and/or red, later turning brown.
Lat/Lng: 53.203666666667, -0.75233333333333
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