This Rubus species is similar to the blackberries (Rubus fruticosus), but is
distinguished by having all leaves divided into three leaflets (five in R.
fruticosus) and by having only a few individual drupelets in the fruit. The
drupelets are covered with a pale 'bloom'.
It is a normal sexually-reproducing species (unlike nearly all members of the R. fruticosus agg.)
It is rare, and some of the records on the map may even refer to the more caesius-like of its hybrids with R. fruticosus agg. It occurs principally on dry, basic (e.g. limestone) soils.