Hi, I think it may be be C canadensis, flowers late spring early summer, Derek.

No, cornus canadensis is a low creeper, not a shrub.

Any ideas, Andrew, could C. kousa be in flower that late?

I think that several of the x nuttallii hybrids flower a bit later, they are C. kousa crossed with C. florida.

Vincent - although there are one or two cornus species that flower in the summer, the leaves do look more like those of C. kousa.
Karan Junker (karan@junker.co.uk) runs a nursery that sells many varieties of cornus, and she is more likely to have an answer than me.

Thanks, Andrew, Teadrinker and Derek, I will try karen and see what she thinks.