Oak galls

I always thought mature oak trees would be the place to look for the great variety of galls that are found on this species, but today I discovered a whole lot of oak saplings, no more than 1.5 metres tall, with a great collection of galls. This photo shows Marble Galls, commonly known as 'oak apples', made by the gall wasp Andricus kollari, common Spangle Galls (Neuroterus quercusbaccarum), Silk Button Spangle Galls (Neuroterus numismalis) and Cupped Spangle Galls (Neuroterus tricolor). Elsewhere on this same oak I found the Artichoke Gall, Andricus foecundatrix. I was astounded to find so many types, but I've just read that our two native oaks together support over 50 different galls - rich hunting at this time of year.