The larva of the Cynipid gall wasp produces galls on Turkey Oak or Lucombe Oak (a hybrid between Turkey Oak and Cork Oak).

The spindle-shaped agamic gall (like a slender cowrie shell or Cornish pasty) is attached to a twig, petiole or midrib, often several in a row. The gall is up to 3 mm long, hard, shiny, sometimes with a few length ridges, green at first becoming reddish brown and spotted, or brown later.

[The sexual gall is on Turkey Oak acorns; the acorn is slightly swollen and may be flushed red or with red 'tentacles'.]

Under "Species", please select "f. agamic" or "f. sexual" as appropriate.  Provide photos showing host leaves/buds/acorns as well as galls

Turkey or Lucombe Oak

Fairly common on host; increasing

British Plant Galls (Redfern & Shirley 2023)