Red galls on Field Maple

Red galls on Field Maple

Observation - Red galls on Field Maple. Description: Irregular red-pink, roughly hemispherical, lumps, (postules?) in random-looking clumps sometimes following veins, on Field Maple sapling leaf.

Irregular red-pink, roughly hemispherical, lumps, (postules?) in random-looking clumps sometimes following veins, on Field Maple sapling leaf.