What Gall?

[KeenTeen17]

This gall was growing underneath an oak leaf, Any idea what it is?

[nutmeg]

I think they are common spangle galls - Neuroterus quercusbaccarum.

[Dogghound]

I agree with nutmeg.

[Hobjob]

Originally Posted by nutmeg

I think they are common spangle galls - Neuroterus quercusbaccarum.

It is the agamic version of this gall - i.e. all females.
Very common and often lots and lots on one leaf.

The sexual life cycle is currant gall on the leaves and also on catkins, but occurs earlier in the season.

It is a gall wasp.

Smooth spangle gall (Neuroterus albipes), Oyster gall (N. anthracinus) and Silk button gall (N. numismalis) are also all common. Cupped spangle gall (N. tricolor) is less common but even more easily confused. It is a minefield