Rubus laciniatus
This is Rubus laciniatus, a distinctive bramble that exhibits cut leaves. It has a few 'English' names, including Parsley-leaved, Fern-leaved and Cut-leaved Bramble. It is a fairly widespread alien across Surrey and can be found locally on Headley Heath (where I took this picture yesterday).
Comments
may I recommend 'Dadland' by Keggie Carew, and Shadowplay by Tim Marshall. Both highly readable and continually jaw-dropping.