Disagreement exists considering the definition of this name. Linsenmaier (1997) treats this taxon as a subspecies of C. ignita. Kunz (1994) considers C. impressa to be a synonym of C. ignita. Morgan (1984) regards C. impressa as a separate species from C. ignita. Here it is meant in the sense given by Morgan (1984).
Throughout England,Wales, Scotland and Ireland but not found on the Orkney and Shetland Islands. Recorded from the Isle of Man, Isle of Wight, the Isles of Scilly and the Channel Islands.
Probably throughout Europe, although authors often treat C. impressa and C. ignita as one species.