Small spindle-shaped gall, with pointed tip, arising from an Oak catkin or leaf. Stunted anthers remain at the base of the gall, which is usually stalked.  Green, then becoming brown, with a ring of hairs around the tip. 

[Note: Sexual generation galls are not known (ref: Redfern and Shirley, 2023)]

Andricus callidoma/malpighii asexual galls are of a very similar shape and size, but arise from an Oak bud

Ensure that your photograph of the gall clearly shows its position on an oak catkin or leaf, and note the host species

native oak trees

Rare (British Plant Galls, Redfern & Shirley, 2023)

Rare

See British Plant Galls (Redfern & Shirley, 2023)