A dog rose (Rosa canina).
The name dog rose conjures up images either roses for dogs, or rose in the shape of dogs. This is neither! Dog rose or Rosa canina is a common species of climbing wild rose native to Europe.
The seeds (hips) of this rose are very rich in vitamin C and used in the preparation of rose-hip tea (see my post Hip Hip Rose). As for the name of this rose, Wikipedia lists two possibilities – common or worthless or as a treatment for the bite from rabid dogs. I think the former is more likely etymology for this plant as it is genuinely common along hedgerows in England. The flowers are pink, have little or no fragrance.
Photographed on one of my summer walks using a Panasonic TZ30 compact camera.